gcc_on=new Image(35,80);
gcc_on.src="gcc_on.gif";
gcc_off=new Image(35,80);
gcc_off.src="gcc_off.gif";

about_on=new Image(35,80);
about_on.src="about_on.gif";
about_off=new Image(35,80);
about_off.src="about_off.gif";

webdev_on=new Image(35,80);
webdev_on.src="webdev_on.gif";
webdev_off=new Image(35,80);
webdev_off.src="webdev_off.gif";

function change(imgName) {
document[imgName].src=eval(imgName + "_on.src");
}

function changeback(imgName) {
document[imgName].src=eval(imgName + "_off.src");
}