// ===================================================================
// Author: Matt Kruse <matt@mattkruse.com>
// WWW: http://www.mattkruse.com/
//
// NOTICE: You may use this code for any purpose, commercial or
// private, without any further permission from the author. You may
// remove this notice from your final code if you wish, however it is
// appreciated by the author if at least my web site address is kept.
//
// You may *NOT* re-distribute this code in any way except through its
// use. That means, you can include it in your product, or your web
// site, or any other form where the code is actually being used. You
// may not put the plain javascript up on your site for download or
// include it in your javascript libraries for download. 
// If you wish to share this code with others, please just point them
// to the URL instead.
// Please DO NOT link directly to my .js files from your site. Copy
// the files to your server and use them there. Thank you.
// ===================================================================

var dynamicOptionListCount=0;
var dynamicOptionListObjects = new Array();

function initDynamicOptionLists(){
  for(var i=0;
      i<dynamicOptionListObjects.length;
      i++){
    var dol = dynamicOptionListObjects[i];
    if(dol.formName!=null){
      dol.form = document.forms[dol.formName];
    }
    else if(dol.formIndex!=null){
      dol.form = document.forms[dol.formIndex];
    }
    else{
      var name = dol.fieldNames[0][0];
      for(var f=0;
          f<document.forms.length;
          f++){
        if(typeof(document.forms[f][name])!="undefined"){
          dol.form = document.forms[f];
          break;
        }
      }
      if(dol.form==null){
        alert("ERROR: Couldn't find form element "+name+" in any form on the page! Init aborted");
        return;
      }
    }
    for(var j=0;
        j<dol.fieldNames.length;
        j++){
      for(var k=0;
          k<dol.fieldNames[j].length-1;
          k++){
        var selObj = dol.form[dol.fieldNames[j][k]];
        if(typeof(selObj)=="undefined"){
          alert("Select box named "+dol.fieldNames[j][k]+" could not be found in the form. Init aborted");
          return;
        }
        if(k==0){
          if(selObj.options!=null){
            for(l=0;
                l<selObj.options.length;
                l++){
              var sopt = selObj.options[l];
              var m = dol.findMatchingOptionInArray(dol.options,sopt.text,sopt.value,false);
              if(m!=null){
                var reselectForNN6 = sopt.selected;
                var m2 = new Option(sopt.text, sopt.value, sopt.defaultSelected, sopt.selected);
                m2.selected = sopt.selected;
                m2.defaultSelected = sopt.defaultSelected;
                m2.DOLOption = m;
                selObj.options[l] = m2;
                selObj.options[l].selected = reselectForNN6;
              }
            }
          }
        }
        if(selObj.onchange==null){
          selObj.onchange = new Function("dynamicOptionListObjects["+dol.index+"].change(this)");
        }
      }
    }
  }
  resetDynamicOptionLists();
}

function resetDynamicOptionLists(theform){
  for(var i=0;
      i<dynamicOptionListObjects.length;
      i++){
    var dol = dynamicOptionListObjects[i];
    if(typeof(theform)=="undefined" || theform==null || theform==dol.form){
      for(var j=0;
          j<dol.fieldNames.length;
          j++){
        dol.change(dol.form[dol.fieldNames[j][0]],true);
      }
    }
  }
}

function DOLOption(text,value,defaultSelected,selected){
  this.text = text;
  this.value = value;
  this.defaultSelected = defaultSelected;
  this.selected = selected;
  this.options = new Array();
  return this;
}

function DynamicOptionList(){
  this.form = null;
  this.options = new Array();
  this.longestString = new Array();
  this.numberOfOptions = new Array();
  this.currentNode = null;
  this.currentField = null;
  this.currentNodeDepth = 0;
  this.fieldNames = new Array();
  this.formIndex = null;
  this.formName = null;
  this.fieldListIndexes = new Object();
  this.fieldIndexes = new Object();
  this.selectFirstOption = true;
  this.numberOfOptions = new Array();
  this.longestString = new Array();
  this.values = new Object();
  this.forValue = DOL_forValue;
  this.forText = DOL_forText;
  this.forField = DOL_forField;
  this.forX = DOL_forX;
  this.addOptions = DOL_addOptions;
  this.addOptionsTextValue = DOL_addOptionsTextValue;
  this.setDefaultOptions = DOL_setDefaultOptions;
  this.setValues = DOL_setValues;
  this.setValue = DOL_setValues;
  this.setFormIndex = DOL_setFormIndex;
  this.setFormName = DOL_setFormName;
  this.printOptions = DOL_printOptions;
  this.addDependentFields = DOL_addDependentFields;
  this.change = DOL_change;
  this.child = DOL_child;
  this.selectChildOptions = DOL_selectChildOptions;
  this.populateChild = DOL_populateChild;
  this.change = DOL_change;
  this.addNewOptionToList = DOL_addNewOptionToList;
  this.findMatchingOptionInArray = DOL_findMatchingOptionInArray;
  if(arguments.length > 0){
    for(var i=0;
        i<arguments.length;
        i++){
      this.fieldListIndexes[arguments[i].toString()] = this.fieldNames.length;
      this.fieldIndexes[arguments[i].toString()] = i;
    }
    this.fieldNames[this.fieldNames.length] = arguments;
  }
  this.index = window.dynamicOptionListCount++;
  window["dynamicOptionListObjects"][this.index] = this;
}

function DOL_findMatchingOptionInArray(a,text,value,exactMatchRequired){
  if(a==null || typeof(a)=="undefined"){
    return null;
  }
  var value_match = null;
  var text_match = null;
  for(var i=0;
      i<a.length;
      i++){
    var opt = a[i];
    if(opt.value==value && opt.text==text){
      return opt;
    }
    if(!exactMatchRequired){
      if(value_match==null && value!=null && opt.value==value){
        value_match = opt;
      }
      if(text_match==null && text!=null && opt.text==text){
        text_match = opt;
      }
    }
  }
  return(value_match!=null)?value_match:text_match;
}

function DOL_forX(s,type){
  if(this.currentNode==null){
    this.currentNodeDepth=0;
  }
  var useNode =(this.currentNode==null)?this:this.currentNode;
  var o = this.findMatchingOptionInArray(useNode["options"],(type=="text")?s:null,(type=="value")?s:null,false);
  if(o==null){
    o = new DOLOption(null,null,false,false);
    o[type] = s;
    useNode.options[useNode.options.length] = o;
  }
  this.currentNode = o;
  this.currentNodeDepth++;
  return this;
}

function DOL_forValue(s){
  return this.forX(s,"value");
}

function DOL_forText(s){
  return this.forX(s,"text");
}

function DOL_forField(f){
  this.currentField = f;
  return this;
}

function DOL_addNewOptionToList(a, text, value, defaultSelected){
  var o = new DOLOption(text,value,defaultSelected,false);
  if(a==null){
    a = new Array();
  }
  for(var i=0;
      i<a.length;
      i++){
    if(a[i].text==o.text && a[i].value==o.value){
      if(o.selected){
        a[i].selected=true;
      }
      if(o.defaultSelected){
        a[i].defaultSelected = true;
      }
      return a;
    }
  }
  a[a.length] = o;
}

function DOL_addOptions(){
  if(this.currentNode==null){
    this.currentNode = this;
  }
  if(this.currentNode["options"] == null){
    this.currentNode["options"] = new Array();
  }
  for(var i=0;
      i<arguments.length;
      i++){
    var text = arguments[i];
    this.addNewOptionToList(this.currentNode.options,text,text,false);
    if(typeof(this.numberOfOptions[this.currentNodeDepth])=="undefined"){
      this.numberOfOptions[this.currentNodeDepth]=0;
    }
    if(this.currentNode.options.length > this.numberOfOptions[this.currentNodeDepth]){
      this.numberOfOptions[this.currentNodeDepth] = this.currentNode.options.length;
    }
    if(typeof(this.longestString[this.currentNodeDepth])=="undefined" ||(text.length > this.longestString[this.currentNodeDepth].length)){
      this.longestString[this.currentNodeDepth] = text;
    }
  }
  this.currentNode = null;
  this.currentNodeDepth = 0;
}

function DOL_addOptionsTextValue(){
  if(this.currentNode==null){
    this.currentNode = this;
  }
  if(this.currentNode["options"] == null){
    this.currentNode["options"] = new Array();
  }
  for(var i=0;
      i<arguments.length;
      i++){
    var text = arguments[i++];
    var value = arguments[i];
    this.addNewOptionToList(this.currentNode.options,text,value,false);
    if(typeof(this.numberOfOptions[this.currentNodeDepth])=="undefined"){
      this.numberOfOptions[this.currentNodeDepth]=0;
    }
    if(this.currentNode.options.length > this.numberOfOptions[this.currentNodeDepth]){
      this.numberOfOptions[this.currentNodeDepth] = this.currentNode.options.length;
    }
    if(typeof(this.longestString[this.currentNodeDepth])=="undefined" ||(text.length > this.longestString[this.currentNodeDepth].length)){
      this.longestString[this.currentNodeDepth] = text;
    }
  }
  this.currentNode = null;
  this.currentNodeDepth = 0;
}

function DOL_child(obj){
  var listIndex = this.fieldListIndexes[obj.name];
  var index = this.fieldIndexes[obj.name];
  if(index <(this.fieldNames[listIndex].length-1)){
    return this.form[this.fieldNames[listIndex][index+1]];
  }
  return null;
}

function DOL_setDefaultOptions(){
  if(this.currentNode==null){
    this.currentNode = this;
  }
  for(var i=0;
      i<arguments.length;
      i++){
    var o = this.findMatchingOptionInArray(this.currentNode.options,null,arguments[i],false);
    if(o!=null){
      o.defaultSelected = true;
    }
  }
  this.currentNode = null;
}

function DOL_setValues(){
  if(this.currentField==null){
    alert("Can't call setValues() without using forField() first!");
    return;
  }
  if(typeof(this.values[this.currentField])=="undefined"){
    this.values[this.currentField] = new Object();
  }
  for(var i=0;
      i<arguments.length;
      i++){
    this.values[this.currentField][arguments[i]] = true;
  }
  this.currentField = null;
}

function DOL_setFormIndex(i){
  this.formIndex = i;
}

function DOL_setFormName(n){
  this.formName = n;
}

function DOL_printOptions(name){
  if((navigator.appName == 'Netscape') &&(parseInt(navigator.appVersion) <= 4)){
    var index = this.fieldIndexes[name];
    var ret = "";
    if(typeof(this.numberOfOptions[index])!="undefined"){
      for(var i=0;
          i<this.numberOfOptions[index];
          i++){
        ret += "<OPTION>";
      }
    }
    ret += "<OPTION>";
    if(typeof(this.longestString[index])!="undefined"){
      for(var i=0;
          i<this.longestString[index].length;
          i++){
        ret += "_";
      }
    }
    document.writeln(ret);
  }
}

function DOL_addDependentFields(){
  for(var i=0;
      i<arguments.length;
      i++){
    this.fieldListIndexes[arguments[i].toString()] = this.fieldNames.length;
    this.fieldIndexes[arguments[i].toString()] = i;
  }
  this.fieldNames[this.fieldNames.length] = arguments;
}

function DOL_change(obj, usePreselected){
  if(usePreselected==null || typeof(usePreselected)=="undefined"){
    usePreselected = false;
  }
  var changedListIndex = this.fieldListIndexes[obj.name];
  var changedIndex = this.fieldIndexes[obj.name];
  var child = this.child(obj);
  if(child == null){
    return;
  }
  if(obj.type == "select-one"){
    if(child.options!=null){
      child.options.length=0;
    }
    if(obj.options!=null && obj.options.length>0 && obj.selectedIndex>=0){
      var o = obj.options[obj.selectedIndex];
      this.populateChild(o.DOLOption,child,usePreselected);
      this.selectChildOptions(child,usePreselected);
    }
  }
  else if(obj.type == "select-multiple"){
    var currentlySelectedOptions = new Array();
    if(!usePreselected){
      for(var i=0;
          i<child.options.length;
          i++){
        var co = child.options[i];
        if(co.selected){
          this.addNewOptionToList(currentlySelectedOptions, co.text, co.value, co.defaultSelected);
        }
      }
    }
    child.options.length=0;
    if(obj.options!=null){
      var obj_o = obj.options;
      for(var i=0;
          i<obj_o.length;
          i++){
        if(obj_o[i].selected){
          this.populateChild(obj_o[i].DOLOption,child,usePreselected);
        }
      }
      var atLeastOneSelected = false;
      if(!usePreselected){
        for(var i=0;
            i<child.options.length;
            i++){
          var m = this.findMatchingOptionInArray(currentlySelectedOptions,child.options[i].text,child.options[i].value,true);
          if(m!=null){
            child.options[i].selected = true;
            atLeastOneSelected = true;
          }
        }
      }
      if(!atLeastOneSelected){
        this.selectChildOptions(child,usePreselected);
      }
    }
  }
  this.change(child,usePreselected);
}

function DOL_populateChild(dolOption,childSelectObj,usePreselected){
  if(dolOption!=null && dolOption.options!=null){
    for(var j=0;
        j<dolOption.options.length;
        j++){
      var srcOpt = dolOption.options[j];
      if(childSelectObj.options==null){
        childSelectObj.options = new Array();
      }
      var duplicate = false;
      var preSelectedExists = false;
      for(var k=0;
          k<childSelectObj.options.length;
          k++){
        var csi = childSelectObj.options[k];
        if(csi.text==srcOpt.text && csi.value==srcOpt.value){
          duplicate = true;
          break;
        }
      }
      if(!duplicate){
        var newopt = new Option(srcOpt.text, srcOpt.value, false, false);
        newopt.selected = false;
        newopt.defaultSelected = false;
        newopt.DOLOption = srcOpt;
        childSelectObj.options[childSelectObj.options.length] = newopt;
      }
    }
  }
}

function DOL_selectChildOptions(obj,usePreselected){
  var values = this.values[obj.name];
  var preselectedExists = false;
  if(usePreselected && values!=null && typeof(values)!="undefined"){
    for(var i=0;
        i<obj.options.length;
        i++){
      var v = obj.options[i].value;
      if(v!=null && values[v]!=null && typeof(values[v])!="undefined"){
        preselectedExists = true;
        break;
      }
    }
  }
  var atLeastOneSelected = false;
  for(var i=0;
      i<obj.options.length;
      i++){
    var o = obj.options[i];
    if(preselectedExists && o.value!=null && values[o.value]!=null && typeof(values[o.value])!="undefined"){
      o.selected = true;
      atLeastOneSelected = true;
    }
    else if(!preselectedExists && o.DOLOption!=null && o.DOLOption.defaultSelected){
      o.selected = true;
      atLeastOneSelected = true;
    }
    else{
      o.selected = false;
    }
  }
  if(this.selectFirstOption && !atLeastOneSelected && obj.options.length>0){
    obj.options[0].selected = true;
  }
  else if(!atLeastOneSelected &&  obj.type=="select-one"){
    obj.selectedIndex = -1;
  }
}