if (document.images) {

        enter1on = new Image();
        enter1on.src = "images/enter-dominion-on.gif"; 
        enter1off = new Image();
        enter1off.src = "images/enter-dominion-off.gif";
        enter2on = new Image();
        enter2on.src = "images/enter-leadgenerators-on.gif"; 
        enter2off = new Image();
        enter2off.src = "images/enter-leadgenerators-off.gif";
        enter3on = new Image();
        enter3on.src = "images/enter-jumpstart-on.gif"; 
        enter3off = new Image();
        enter3off.src = "images/enter-jumpstart-off.gif";

}
function changeImages(){
        if(document.images){
                for (var i=0; i<changeImages.arguments.length; i+=2) {
                        document[changeImages.arguments[i]].src = eval(changeImages.arguments[i+1] + ".src");
                }
        }
}