Try this one
Just put it in your HTML code
<script type="text/javascript">
function disableRightClick(btnClick) {
if (navigator.appName == "Netscape" && btnClick.which == 3) { // check for netscape and right click
alert("Right Click is disabled");
return false;
}
else if (navigator.appName =="Microsoft Internet Explorer" && event.button == 2) { // for IE and Right Click
alert("Right Click is disabled");
return false;
}
}
document.onmousedown = disableRightClick;
</script>