function changeImage() {
if (document.getElementById) {
document.getElementById("services").src="images/but-services_f2.jpg";
}
else if (document.all) {
document.all["services"].src="images/but-services_f2.jpg";
}
else if (document.layers) {
document.layers["services"].src="images/but-services_f2.jpg";
}
}