var tables = getElementsByClassName("voted");

for (var i=0, ii=tables.length; i<ii; i++)
{
	// get all tbody elements inside this table
	var tbodys = tables[i].getElementsByTagName("tbody");	
	
	// for each one...
	for (var j=0, jj=tbodys.length; j<jj; j++)
	{	
		// get all tr elements inside this tbody
		var trs = tbodys[j].getElementsByTagName("tr");
		
		// for every SECOND ONE of those...
		for (var k=1, kk=trs.length; k<kk; k+=2)
		{
			// assign it the className "alt"
			trs[k].className = "alt";
		}
	}
}

function getElementsByClassName(className)
{
	// get all elements in the document
	if (document.all)
	{
		var allElements = document.all;
	}
	else
	{
		var allElements = document.getElementsByTagName("*");
	}
	
	var foundElements = [];
	for (var i = 0, ii = allElements.length; i < ii; i++)
	{
		if (allElements[i].className == className)
		{
			foundElements[foundElements.length] = allElements[i];
		}
	}
	
	return foundElements;
}