addEventListener issue

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giantpiazza31

I'm trying to add an event handler for to my body, and for some reason which I can't figure out, it only works on Google Chrome. I wouldn't expect it to work in IE, but am wondering why it's not working in Firefox.

Here's the relevant parts of the code:

Javascript (in an external file)

var body = document.body;
body.addEventListener("load", Foo(), false);

function Foo(){	
	addEventListener(document.getElementsByName("start"),"click", alert("hello"), false);
}

HTML

<html>
	<head>
		<title>BREAKOUT!</title>
		<script src="breakout.js" type="text/Javascript" >
		</script>
		<LINK REL="stylesheet" HREF="breakout.css" TYPE="text/css">
	</head>

<body id="body">
<!-- etc.... -->

Declan1991

Well, it shouldn't really work at all! Foo() is the return value of the function, in this case nothing. What you actually want is the function, so you just use Foo without the brackets (like #'Foo if you've ever studied Lisp).

var body = document.body;
body.addEventListener("load", Foo, false);

function Foo(){	
	addEventListener(document.getElementsByName("start"),"click", [COLOR="Red"][B]function() {[/B][/COLOR]alert("hello")[COLOR="Red"][B];}[/B][/COLOR], false);
}

The anonymous function is for the same reason, equivalent to lambda in Lisp.

As a matter of interest, John McCarthy who created Lisp died recently, and Lisp and JavaScript share many similarities.