var oldTab = "tab1";

function tabhighlight(page, newTab){
	if(newTab != oldTab){		
		var baseFolder = "img/";
		var basePage = page + "_";
		var newTabPic = baseFolder + basePage + newTab + "_h.jpg";
		var oldTabPic = baseFolder + basePage + oldTab + ".jpg";
		
		document.getElementById(newTab).src=newTabPic;
		document.getElementById(oldTab).src=oldTabPic;
		
		oldTab = newTab;
	}
}