function DynamicOptionList()
{
	if(arguments.length < 2)
	{
		alert("Not enough arguments in DynamicOptionList()");
	}
	this.target = arguments[0];
	this.dependencies = new Array();
	for(var i=1;i<arguments.length;i++)
	{
		this.dependencies[this.dependencies.length] = arguments[i];
	}
	this.form = null;
	this.dependentValues = new Object();
	this.defaultValues = new Object();
	this.options = new Object();
	this.optionstyle = new Object();
	this.delimiter = "|";
	this.longestString = "";
	this.numberOfOptions = 0;
	this.addOptions = DynamicOptionList_addOptions;
	this.populate = DynamicOptionList_populate;
	this.setDelimiter = DynamicOptionList_setDelimiter;
	this.setDefaultOption = DynamicOptionList_setDefaultOption;
	this.printOptions = DynamicOptionList_printOptions;
	this.init = DynamicOptionList_init;
}

function DynamicOptionList_setDelimiter(val)
{
	this.delimiter = val;
}

function DynamicOptionList_setDefaultOption(condition, val)
{
	if(typeof this.defaultValues[condition] == "undefined" || this.defaultValues[condition]==null)
	{
		this.defaultValues[condition] = new Object();
	}
	for(var i=1;i<arguments.length;i++)
	{
		this.defaultValues[condition][arguments[i]]=1;
	}
}
function DynamicOptionList_init(theform)
{
	this.form = theform;
	this.populate();
}
function DynamicOptionList_addOptions(dependentValue)
{
	if(typeof this.options[dependentValue] != "object")
	{
		this.options[dependentValue] = new Array();
		/*this.optionstyle[dependentValue] = new Array();*/
	}
	for(var i=1;i<arguments.length;i+=3) /* changed to 3 by sihui*/
	{
		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];
		this.options[dependentValue][this.options[dependentValue].length] = arguments[i+2];
		/*this.optionstyle[dependentValue][this.optionstyle[dependentValue].length] = arguments[i+2];*/
		
	}
}

function DynamicOptionList_printOptions()
{
	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);
	}
}

function DynamicOptionList_populate()
{
	var theform = this.form;
	var i,j,obj,obj2;
	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(!dependentValuesInitialized)
		{
			dependentValuesInitialized = true;
			for(j=0;j<sel.options.length;j++)
			{
				if(sel.options[j].selected)
				{
					this.dependentValues[sel.options[j].value] = true;
				}
			}
		}
		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];
	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;
	for(i in this.dependentValues)
	{
		if(typeof this.options[i] == "object")
		{
			var o = this.options[i];
			/*var s = this.optionstyle[i];*/
			for(j=0;j<o.length;j+=3)  /* changed to 3*/
			{
				var text = o[j];
				var val = o[j+1];
				var sty = o[j+2];
			 
				
				var styledoption = new Option(text, val, false, false);
				
			    styledoption.style.color=sty;
				
				targetSel.options[targetSel.options.length] = styledoption;
				
				
				/* added for testing by sihui*/
				if(typeof this.defaultValues[i] != "undefined" && this.defaultValues[i]!=null)
				{
					for(def in this.defaultValues[i])
					{
						if(def == val)
						{
							targetSelected[val] = true;
						}
					}
				}
			}
		}
	}
	targetSel.selectedIndex=-1;
	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;
		}
	}
}