if (document.images){
img1on=new Image();
img1on.src="im/mw_.gif";
img1off=new Image();
img1off.src="im/mw.gif";
img1click=new Image();
img1click.src="im/mw_d.gif";

}
function imgOn(imgName){
if (document.images){
document[imgName].src=eval(imgName+"on.src");
}
}
function imgOff(imgName){
if (document.images){
document[imgName].src=eval(imgName+"off.src");
}
}
function imgClick(imgName){
if (document.images){
document.imgname=imgName
document[imgName].src=eval(imgName+"click.src");
}
}