function getElementsByClassName(needle) {
	var my_array = document.getElementsByTagName("*");
	var retvalue = new Array();
	var i;
	var j;

	for (i=0,j=0;i<my_array.length;i++)
	{
		var c = " " + my_array[i].className + " ";
		if (c.indexOf(" " + needle + " ") != -1) 
			retvalue[j++] = my_array[i];
	}
	return retvalue;
}
var classname = 'product_thumb'; 

function prod_mouseover()
{
	var divs = getElementsByClassName(classname)
	for(i=0; i <divs.length;i++)
	{
		if(divs[i].className == 'product_thumb')
		{
			divs[i].className = 'product_thumb_hover';
			classname = 'product_thumb_hover';
		}
		else
		{
			divs[i].className = 'product_thumb';
			classname = 'product_thumb';
		}
	}
}