function DynamicOptionList() {
	if (arguments.length < 2) { alert("Not enough arguments in DynamicOptionList()"); }
	// Name of the list containing dynamic values
	this.target = arguments[0];
	// Set the lists that this dynamic list depends on
	this.dependencies = new Array();
	for (var i=1; i<arguments.length; i++) {
		this.dependencies[this.dependencies.length] = arguments[i];
		}
	// The form this list belongs to
	this.form = null;
	// Place-holder for currently-selected values of dependent select lists
	this.dependentValues = new Object();
	// Hold default values to be selected for conditions
	this.defaultValues = new Object();
	// Storage for the dynamic values
	this.options = new Object();
	// Delimiter between dependent values
	this.delimiter = "|";
	// Logest string currently a potential options (for Netscape)
	this.longestString = "";
	// The total number of options that might be displayed, to build dummy options (for Netscape)
	this.numberOfOptions = 0;
	// Method mappings
	this.addOptions = DynamicOptionList_addOptions;
	this.populate = DynamicOptionList_populate;
	this.setDelimiter = DynamicOptionList_setDelimiter;
	this.setDefaultOption = DynamicOptionList_setDefaultOption;
	this.printOptions = DynamicOptionList_printOptions;
	this.init = DynamicOptionList_init;
	}

// Set the delimiter to something other than | when defining condition values
function DynamicOptionList_setDelimiter(val) {
	this.delimiter = val;
	}

// Set the default option to be selected when the list is painted
function DynamicOptionList_setDefaultOption(condition, val) {
	this.defaultValues[condition] = val;
	}

// Init call to map the form to the object and populate it
function DynamicOptionList_init(theform) {
	this.form = theform;
	this.populate();
	}

// Add options to the list.
// Pass the condition string, then the list of text/value pairs that populate the list	
function DynamicOptionList_addOptions(dependentValue) {
	if (typeof this.options[dependentValue] != "object") { this.options[dependentValue] = new Array(); }
	for (var i=1; i<arguments.length; i+=2) {
		// Keep track of the longest potential string, to draw the option list
		if (arguments[i].length > this.longestString.length) {
			this.longestString = arguments[i];
			}
		this.numberOfOptions++;
		this.options[dependentValue][this.options[dependentValue].length] = arguments[i];
		this.options[dependentValue][this.options[dependentValue].length] = arguments[i+1];
		}
	}

// Print dummy options so Netscape behaves nicely
function DynamicOptionList_printOptions() {
	// Only need to write out "dummy" options for Netscape
    if ((navigator.appName == 'Netscape') && (parseInt(navigator.appVersion) <= 4)){
		var ret = "";
		for (var i=0; i<this.numberOfOptions; i++) { 
			ret += "<OPTION>";
			}
		ret += "<OPTION>"
		for (var i=0; i<this.longestString.length; i++) {
			ret += "_";
			}
		document.writeln(ret);
		}
	}

// Populate the list
function DynamicOptionList_populate()
{
	var theform = this.form;
	var i,j,obj,obj2;
	// Get the current value(s) of all select lists this list depends on
	this.dependentValues = new Object;
	var dependentValuesInitialized = false;
	for (i=0; i<this.dependencies.length;i++)
	{
		var sel = theform[this.dependencies[i]];
		var selName = sel.name;
		// If this is the first dependent list, just fill in the dependentValues
		if (!dependentValuesInitialized)
		{
			dependentValuesInitialized = true;
			for (j=0; j<sel.options.length; j++)
			{
				if (sel.options[j].selected)
				{
					this.dependentValues[sel.options[j].value] = true;
				}
			}
		}
		// Otherwise, add new options for every existing option
		else {
			var tmpList = new Object();
			var newList = new Object();
			for (j=0; j<sel.options.length; j++) {
				if (sel.options[j].selected) {
					tmpList[sel.options[j].value] = true;
					}
				}
			for (obj in this.dependentValues) {
				for (obj2 in tmpList) {
					newList[obj + this.delimiter + obj2] = true;
					}
				}
			this.dependentValues = newList;
			}
		}

	var targetSel = theform[this.target];
		
	// Store the currently-selected values of the target list to maintain them (in case of multiple select lists)
	var targetSelected = new Object();
	for (i=0; i<targetSel.options.length; i++) {
		if (targetSel.options[i].selected) {
			targetSelected[targetSel.options[i].value] = true;
			}
		}

	targetSel.options.length = 0; // Clear all target options
		
	for (i in this.dependentValues) {
		if (typeof this.options[i] == "object") {
			var o = this.options[i];
			for (j=0; j<o.length; j+=2) {
				var text = o[j];
				var val = o[j+1];
				//alert(val + ' = ' + text);
				targetSel.options[targetSel.options.length] = new Option(text, val, false, false);
				if (this.defaultValues[i] == val) {
					targetSelected[val] = true;
					}
				}
			}
		}
	targetSel.selectedIndex=-1;
	
	// Select the options that were selected before
	for (i=0; i<targetSel.options.length; i++) {
		if (targetSelected[targetSel.options[i].value] != null && targetSelected[targetSel.options[i].value]==true) {
			targetSel.options[i].selected = true;
			}
		}
	}
	
//These functions begin the section for moving options from one listbox to another and moving up and down

// -------------------------------------------------------------------
// selectUnselectMatchingOptions(select_object,regex,select/unselect,true/false)
//  This is a general function used by the select functions below, to
//  avoid code duplication
// -------------------------------------------------------------------
function selectUnselectMatchingOptions(obj,regex,which,only) {
	if (window.RegExp) {
		if (which == "select") {
			var selected1=true;
			var selected2=false;
			}
		else if (which == "unselect") {
			var selected1=false;
			var selected2=true;
			}
		else {
			return;
			}
		var re = new RegExp(regex);
		for (var i=0; i<obj.options.length; i++) {
			if (re.test(obj.options[i].text)) {
				obj.options[i].selected = selected1;
				}
			else {
				if (only == true) {
					obj.options[i].selected = selected2;
					}
				}
			}
		}
	}
		
// -------------------------------------------------------------------
// selectAllOptions(select_object)
//  This function takes a select box and selects all options (in a 
//  multiple select object). This is used when passing values between
//  two select boxes. Select all options in the right box before 
//  submitting the form so the values will be sent to the server.
// -------------------------------------------------------------------
function selectAllOptions(obj) {
	for (var i=0; i<obj.options.length; i++) {
		obj.options[i].selected = true;
		}
	}
	
// -------------------------------------------------------------------
// moveSelectedOptions(select_object,select_object[,autosort(true/false)[,regex]])
//  This function moves options between select boxes. Works best with
//  multi-select boxes to create the common Windows control effect.
//  Passes all selected values from the first object to the second
//  object and re-sorts each box.
//  If a third argument of 'false' is passed, then the lists are not
//  sorted after the move.
//  If a fourth string argument is passed, this will function as a
//  Regular Expression to match against the TEXT or the options. If 
//  the text of an option matches the pattern, it will NOT be moved.
//  It will be treated as an unmoveable option.
//  You can also put this into the <SELECT> object as follows:
//    onDblClick="moveSelectedOptions(this,this.form.target)
//  This way, when the user double-clicks on a value in one box, it
//  will be transferred to the other (in browsers that support the 
//  onDblClick() event handler).
// -------------------------------------------------------------------
function moveSelectedOptions(from,to) {
	// Unselect matching options, if required
	if (arguments.length>3) {
		var regex = arguments[3];
		if (regex != "") {
			unSelectMatchingOptions(from,regex);
			}
		}
	// Move them over
	for (var i=0; i<from.options.length; i++) {
		var o = from.options[i];
		if (o.selected) {
			to.options[to.options.length] = new Option( o.text, o.value, false, false);
			}
		}
	// Delete them from original
	for (var i=(from.options.length-1); i>=0; i--) {
		var o = from.options[i];
		if (o.selected) {
			from.options[i] = null;
			}
		}
	if ((arguments.length<3) || (arguments[2]==true)) {
		sortSelect(from);
		sortSelect(to);
		}
	from.selectedIndex = -1;
	to.selectedIndex = -1;
	}

// -------------------------------------------------------------------
// moveAllOptions(select_object,select_object[,autosort(true/false)[,regex]])
//  Move all options from one select box to another.
// -------------------------------------------------------------------
function moveAllOptions(from,to) {
	selectAllOptions(from);
	if (arguments.length==2) {
		moveSelectedOptions(from,to);
		}
	else if (arguments.length==3) {
		moveSelectedOptions(from,to,arguments[2]);
		}
	else if (arguments.length==4) {
		moveSelectedOptions(from,to,arguments[2],arguments[3]);
		}
	}

// -------------------------------------------------------------------
// swapOptions(select_object,option1,option2)
//  Swap positions of two options in a select list
// -------------------------------------------------------------------
function swapOptions(obj,i,j) {
	var o = obj.options;
	var i_selected = o[i].selected;
	var j_selected = o[j].selected;
	var temp = new Option(o[i].text, o[i].value, o[i].defaultSelected, o[i].selected);
	var temp2= new Option(o[j].text, o[j].value, o[j].defaultSelected, o[j].selected);
	o[i] = temp2;
	o[j] = temp;
	o[i].selected = j_selected;
	o[j].selected = i_selected;
	}
	
// -------------------------------------------------------------------
// moveOptionUp(select_object)
//  Move selected option in a select list up one
// -------------------------------------------------------------------
function moveOptionUp(obj) {
	// If > 1 option selected, do nothing
	var selectedCount=0;
	for (i=0; i<obj.options.length; i++) {
		if (obj.options[i].selected) {
			selectedCount++;
			}
		}
	if (selectedCount > 1) {
		return;
		}
	// If this is the first item in the list, do nothing
	var i = obj.selectedIndex;
	if (i == 0) {
		return;
		}
	swapOptions(obj,i,i-1);
	obj.options[i-1].selected = true;
	}

// -------------------------------------------------------------------
// moveOptionDown(select_object)
//  Move selected option in a select list down one
// -------------------------------------------------------------------
function moveOptionDown(obj) {
	// If > 1 option selected, do nothing
	var selectedCount=0;
	for (i=0; i<obj.options.length; i++) {
		if (obj.options[i].selected) {
			selectedCount++;
			}
		}
	if (selectedCount > 1) {
		return;
		}
	// If this is the last item in the list, do nothing
	var i = obj.selectedIndex;
	if (i == (obj.options.length-1)) {
		return;
		}
	swapOptions(obj,i,i+1);
	obj.options[i+1].selected = true;
	}