function getElementsByClassName(className, tag, elm){
		var testClass = new RegExp("(^|\\\\s)" + className + "(\\\\s|$)");
		var tag = tag || "*";
		var elm = elm || document;
		var elements = (tag == "*" && elm.all)? elm.all : elm.getElementsByTagName(tag);
		var returnElements = [];
		var current;
		var length = elements.length;
		for(var i=0; i<length; i++){
				current = elements[i];
				if(testClass.test(current.className)){
						returnElements.push(current);
				}
		}
		return returnElements;
}

function colorizeTables()
{
		var colorarr = new Array('#efefef', '#fff');
		var tables = getElementsByClassName('us_table')
		for(var x = 0; x < tables.length; x++)
		{
				var rows = tables[x].getElementsByTagName('tr');
				for(var i = j = 0; i < rows.length; i++)
				{
					if(i > 0);
					{
							rows[i].style.backgroundColor = colorarr[j % colorarr.length];
							j++;
					}
				}
		}
}