Popup window in the index.php

[ChargeIT]

I want to make a link that open a popup window with a specific size ex 500x400 pixels.

 

I understand that i should use javascript but i dont know where (what file/s) i should put the script?

 

I can't get it to work, when i click on the link it says 'Error on page.'

 

index.php in the Languages/svenska directory are as follows:

...

H?r kommer det snart lite information om bl a:<br>

<a href=java script:popUp (http://www.chargeit.se/catalog/images/ombatterier.htm)>Batterier</a><br>

...

 

Where should I put this script? Now i have put in the index.php in the catalog directory (line 43):

...

<script LANGUAGE="JavaScript">

<!-- Begin

function popUp(URL) {

day = new Date();

id = day.getTime();

eval("page" + id + " = window.open(URL, '" + id + "', 'toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=0,width=56

0,height=400,left = 360,top = 312');");

}

// End -->

</script>

...

 

The adress to the shop are: http://www.chargeit.se/catalog/index.php

 

Please help me, i'm a Rookie!