undefined data in javascript

Matt

I have no idea why id is undefined in the arrow below. Please advise. Thanks!!

<html>
<head>
<script type="text/javascript">
var id;
function window_onload()
{
id = "8888";
alert("ID = " + id);
}
</script>
</head>
<H2>Page 2</H2>
<body onload="window_onload()">
<P>id = <script type="text/javascript">document.write(id);</script> //<****
</body>
</html>

Jul 20 '05 #1

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2267

Randy Webb

Matt wrote:

I have no idea why id is undefined in the arrow below. Please advise. Thanks!!

<html>
<head>
<script type="text/javascript">
var id;
function window_onload()
{
id = "8888";
alert("ID = " + id);
}
</script>
</head>
<H2>Page 2</H2>
<body onload="window_onload()">
<P>id = <script type="text/javascript">document.write(id);</script> //<****
</body>
</html>

Because its value is not set until the onload event fires, which is
*after* you try to write it, so its not set yet. So, you get undefined
(which it is).

--
Randy
Chance Favors The Prepared Mind
comp.lang.javascript FAQ - http://jibbering.com/faq/

Jul 20 '05 #2

mscir

Randy Webb wrote:

Matt wrote:
I have no idea why id is undefined in the arrow below. Please advise.
Thanks!!

<html>
<head>
<script type="text/javascript">
var id;
function window_onload()
{
id = "8888";
alert("ID = " + id);
}
</script>
</head>
<H2>Page 2</H2>
<body onload="window_onload()">
<P>id = <script type="text/javascript">document.write(id);</script>
//<****
</body>
</html>

Because its value is not set until the onload event fires, which is
*after* you try to write it, so its not set yet. So, you get undefined
(which it is).

Yup, I tried this:

<html>
<head>
<script type="text/javascript">
var id;
function window_onload() {
//id = "8888";
alert("ID = " + id);
}
</script>
</head>

<body onload="window_onload()">
<script type="text/javascript">
var id="8888";
</script>
<form>
<P>id = <script type="text/javascript">document.write(id);</script>
</form>
</body>
</html>

Jul 20 '05 #3

Lee

Matt said:

I have no idea why id is undefined in the arrow below. Please advise. Thanks!!

<html>
<head>
<script type="text/javascript">
var id;
function window_onload()
{
id = "8888";
alert("ID = " + id);
}
</script>
</head>
<H2>Page 2</H2>
<body onload="window_onload()">
<P>id = <script type="text/javascript">document.write(id);</script> //<****
</body>
</html>

id isn't defined until the onLoad event handler executes,
but the inline script tries to write its value as the page is still loading.

Jul 20 '05 #4

mscir

oops... forgot to clean it up first

<html>
<head>
<script type="text/javascript">
var id;
function window_onload() {
alert("ID = " + id);
}
</script>
</head>

<body onload="window_onload()">
<script type="text/javascript">
id="8888";
</script>
<P>id = <script type="text/javascript">document.write(id);</script>
</body>
</html>

Jul 20 '05 #5

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