var W3CDOM = (document.createElement && document.getElementsByTagName);

var imgOver = new Array();
var imgOff = new Array();

window.onload = init;

function init()
{
	if (!W3CDOM) return;
	//single rollover top nav
	var nav = document.getElementById('navs');
	var imgs = nav.getElementsByTagName('img');
        var rTest = /_on\.gif$/;
	  for (i=0; i<imgs.length; i++) 
		{
		var src = imgs[i].src;
		if(!rTest.test(src))
		  {
		   imgs[i].onmouseover = over;
		   imgs[i].onmouseout = off;
		   var suffix = imgs[i].src.substring(imgs[i].src.lastIndexOf('.'));
		   imgOff[i] = new Image();
		   imgOff[i].src = imgs[i].src;
		   imgOver[i] = new Image();
		   imgOver[i].src = imgs[i].src.substring(0,imgs[i].src.lastIndexOf('.')) + "_over" + suffix;
		   imgs[i].number = i;
		  }
	  }
}

function over() 
{
	this.src = imgOver[this.number].src;
}

function off() 
{
	this.src = imgOff[this.number].src;
}