if (navigator.appName.indexOf("Netscape") != -1){
document.captureEvents(Event.MOUSEDOWN)
document.onmousedown = checkClick
function checkClick(ev) {
        if (ev.which != 1) {
                alert("Right click has been disabled.")   // You can delete this line if you want
                return false
        }
}	
}
if (navigator.appName.indexOf("Explorer") != -1){
document.body.onmousedown=new Function("if (event.button==2||event.button==3)alert('hey, hey, The right mouse button has been disabled, Sorry')")
}