How to pass this to an event handler?

[tinfanide]

<script type="text/javascript" src="a.js"></script><script>func("f");function f(){alert("this is a function.");}</script>

// a.jsfunction func(a){document.body.onmousedown = a;}

I want to pass "f" to the handler in the file a.js.But it says

// IE debugger SCRIPT5007: Unable to set value of the property 'onmousedown': object is null or undefined

[eTianbun]

Well, no error in your code tho, but the only thing you aint doing right, is that you are passing a string ('f') into the func function, instead of a reference. It should be:

func(f) // without quotes!

[tinfanide]

Well, no error in your code tho, but the only thing you aint doing right, is that you are passing a string ('f') into the func function, instead of a reference. It should be:

func(f) // without quotes!

This doesn't work.I think the problem mainly lies in the a.js filewheredocument.body returns null (of course there is no document.body within the a.js file) It seems that I cannot store the mouse event in a seperate JS file.

[eTianbun]

I know, thats why i said 'no error in your code...' I knew even tho you changed that, it will not fix the prob, but i just wanted to point that out.

[tinfanide]

So it is never possible to do this way?

[eTianbun]

Your code should work tho! Have you tryd it in other browsers?

Edited July 10, 2012 by CodeName

[justsomeguy]

Are you running that code before the body has loaded?

[dsonesuk]

try using document on its own without '.body'

document.onmousedown = a;

[Don E]

Using dsonesuk's suggestion and passing f without quotes as how CodeName suggested should work.

[tinfanide]

Yes. It works.Thanks for you all discussing this code.

<script type="text/javascript" src="a.js"></script><script> // passing a function does not need quotes ("")func(f);function f(){alert("this is a function.");}</script> // a.jsfunction func(a){   // It seems that after loading the HTML document, loading the js file precedes loading the document.body.   // It seems that that's why document.body is null when loading this js file   document.onmousedown = a;}