the pages have the same html tags as I have shown except for the IDs are different
Are you saying tha you do *NOT* have *ALL* of those IDs on the *SAME PAGE*???

In this code:
Code:
function windowOpen() 
{
    document.getElementById('killstreakwin').style.visibility='visible';
    document.getElementById('standardwin').style.visibility='visible';
    .. etc. ...
}
the VERY FIRST of those id's that do NOT exist on the SAME PAGE will indeed cause an error and the function will stop working.

So if you have "killstreakwin" in one window and "standardwin" in another window, *OF COURSE* it will never work.

I *can* suggest a way to make it work, if that's the case.

Oh, heck...I'll just post it:
Code:
var winIDs = [
    'killstreakwin',
    'standardwin',
    'hardenedwin',
    'veteranwin',
    'prestigewin',
    'perkswin',
    'copycatwin',
    'martyrdomwin',
    'finalstandwin',
    'painkillerwin',
    'rankswin',
    'prestigewin',
    'primarywin',
    'secondarywin',
    'attachmentswin'
    ];

function windowOpen()
{
    for ( var w = 0; w < winIDs.length; ++w )
    {
        var div = document.getElementById(winIDs[w]);
        if ( div != null ) div.style.visibility = "visible";
    }
}
function windowClose()
{
    for ( var w = 0; w < winIDs.length; ++w )
    {
        var div = document.getElementById(winIDs[w]);
        if ( div != null ) div.style.visibility = "hidden";
    }
}