function tg_altRows(tableClass, altClass, ignore) {
	

	var rows, arow;
	
	var tables = document.getElementsByTagName("table");
	var rowCount = 0;
	
	// check all tablees for swapClass
	for(var i=0;i<tables.length;i++) {
		if(tables.item(i).className == tableClass) {
			atable = tables.item(i);
			rows = atable.getElementsByTagName("tr");
			
			for(var j=ignore;j<rows.length;j++) {
				arow = rows.item(j);
				if(arow.nodeName == "TR") {
					if(rowCount % 2 && arow.className != "hilite") { // do not change row colour if it is hightlighted!
						arow.className = arow.className+" "+altClass;
					} else {
						// default case - leave as it is!
					}
					rowCount++;
				}
			}
			
			rowCount = 0;
		}
		
	}
	
}