//var NS4 = (document.layers)?true:false;
var IE4 = (document.all)?true:false;
var NS4 = (IE4)?false:true;

function _struct(child,childcaption,parent){
this.child = child;
this.childcaption = childcaption;
this.parent = parent;
}
function _addobject(child,childcaption,parent){
var obj = new _struct();
obj.child = child;
obj.childcaption = childcaption;
obj.parent = parent;
return(obj);
}
function insertEntry(child,childcaption,parent){
    if(child.length > 0 ){
        for(var i=0;i<this.length;i++)
            if(this.items[i].child == child)
                return;
        this.items[this.length++] = _addobject(child,childcaption,parent);
    }
}
function OptionCollection(){
this.length=0;
this.items = new Object();
this.Add=insertEntry
}

function clearSelect(oSelect){
var iCount=0;
if(!oSelect) return;
iCount = oSelect.options.length;
for(var i=0;i<iCount;i++){
    if(IE4)
        oSelect.options.remove(0);
    else if(NS4)
        oSelect.options[0]=null;
}
}
function addOptions(oSelect,olist,parent){
    var elOption;
    var idxSelect=0;

    //check arguments.
    if((!olist) || (!oSelect))return;
    if(parent.length <= 0)  return;

    //now looop through all the list items only entering relevant options.
    clearSelect(oSelect);

    //add a blank list
    elBlankOption = new Option();
    elBlankOption.text = "";
    if(NS4) oSelect.options[0] = elBlankOption
    else if(IE4) oSelect.options.add(elBlankOption,0)

    elBlankOption.value = "";
    for(var i=0;i<olist.length;i++){
        //only the child entries of the parent
        if(olist.items[i].parent == parent){
            elOption = new Option();
            //now IE and NS have a different way to handle object creation.
            if(NS4){
                elOption.value = olist.items[i].child
                elOption.text = olist.items[i].childcaption
                oSelect.options[idxSelect] = elOption
            }else if(IE4){
                elOption.value = olist.items[i].child
                elOption.text = olist.items[i].childcaption
                oSelect.options.add(elOption,idxSelect)
            }
            idxSelect++;
            delete(elOption);
        }
    }
}

function clearOptions(szSelect,szForm){
if(szSelect.length <= 0 || szForm.length <=0)
    alert("error:clearOption must pass arguments");
if(IE4)
clearSelect(document.all.item(szSelect));
else if(NS4)
clearSelect(eval('document.' + szForm + '.' + szSelect));
}

function listAllOptions(szSelect,szForm,olist){
    var elOption;
    var idxSelect=0;
    var oSelect = new Object();

    //check arguments.
    if(!olist)return;

    if(IE4)
         oSelect = document.all.item(szSelect);
    else if(NS4)
        oSelect = eval('document.' + szForm + '.' + szSelect);

    if(!oSelect)return;

    //now looop through all the list items entering all
    clearSelect(oSelect);
    for(var i=0;i<olist.length;i++){
        elOption = new Option();
        //now IE and NS have a different way to handle object creation.
        if(NS4){
            elOption.value = olist.items[i].child
            elOption.text = olist.items[i].childcaption
            oSelect.options[idxSelect] = elOption
        }else if(IE4){
            elOption.value = olist.items[i].child
            elOption.text = olist.items[i].childcaption
            oSelect.options.add(elOption,idxSelect)
        }
        idxSelect++;
        delete(elOption);
    }
}

function UpdateSelect(szSelect,szForm,szParent,olist){
if(IE4)
addOptions(document.all.item(szSelect),olist,szParent);
else if(NS4)
addOptions(eval('document.' + szForm + '.' + szSelect),olist,szParent);
}