Intercepting right-clicks in FireFox.

[Disiance]

I have script that triggers off when the user right clicks in IE, but doesn't work in FireFox.

var whoami=navigator.userAgent.toLowerCase(); //use lower case name
var is_ie = (whoami.indexOf("msie") != -1); //does name contain 'msie'?

function setRClick(e) {
	var message = "Right click disabled";
	if(!document.rightClickDisabled) { // initialize
		if(document.layers) {
			document.captureEvents(Event.MOUSEDOWN);
			document.onmousedown = setRClick;
		}
		else {
			document.oncontextmenu = setRClick;
		}
		return document.rightClickDisabled = true;
	}
	if (is_ie) {		//Internet Explorer




		//This code to execute when right button is clicked
		//Have taken out the "if (is_ie)" condition, that doesn't help, and makes it not work in IE




	}
	return false;
}