function Is() {
    this.ns  = ((navigator.appName == "Netscape") && (parseInt(navigator.appVersion) >= 3 ));
    this.ie  = ((navigator.appName == "Microsoft Internet Explorer") && (parseInt(navigator.appVersion) >= 3 ));
}

var is = new Is();
var selected = 'none';
var selectedItem = 'none';

// DOCUMENT OBJECT SWITCH (Used for building cross_browser functions)
if(is.ns) {
    doc = "document";
    sty = "";
} else if(is.ie) {
    doc = "document.all";
    sty = ".style";
}

function _onmouseover(id)
{
	if( selected != 'none') 
	{
		var old_page = eval(doc + "." + selected + sty);
		old_page.visibility = "hidden";
	}
	if( selectedItem != 'none' )
	{
		var old_item = eval(doc + "." + selectedItem + sty);
		old_item.visibility = "hidden";
		selectedItem = 'none';
	}

	var new_page = eval(doc + "." + id + sty);
	new_page.visibility = "visible";

	selected = id;
}

function _onmouseoverItem(itemId)
{
	if( selectedItem != 'none') 
	{
		var old_page = eval(doc + "." + selectedItem + sty);
		old_page.visibility = "hidden";
	}

	var new_page = eval(doc + "." + itemId + sty);
	new_page.visibility = "visible";

	selectedItem = itemId;
}

function _chooseCurrentLink(linkId)
{
	var currLnk = eval(doc + "." + linkId + sty);
	currLnk.backgroundColor = "#f7b510";
}