document.getElementById("tab1").style.backgroundImage = "URL(/images/selectedTabLeft.gif)";
document.getElementById("tabAnchor1").style.backgroundImage = "URL(/images/selectedTabRight.gif)";

document.getElementById("tabAnchor1").onmouseover=function() {this.className+=" selectedHover";}
document.getElementById("tabAnchor1").onmouseout=function() {this.className=this.className.replace(new RegExp(" selectedHover\\b"), "");}