Function Not Defined ?

This is an admittedly convoluted script, so I'm not surprised it's a bit buggy.Basically, I'm arranging several hundred small divs on a page. This code writes each of them onload, and checks urlArray to see if the specific div being written has a function attached to it, then enables onmouseover/onmouseout hand pointer/default pointers to it, and, of course, runs the function onclick.

var urlArray = ["main", "none", "none", "none", ... (snip) ]
var i = 0;
function writeDivs(){[code]....

The script as it appears here runs great in chrome, but Firefox tells me that "main" is undefined whenever I click or roll over the div, and IE says "object expected" when I click."main" is the name of a function defined in an external js file (though pasting the function into the main document doesn't do anything).In fact, the whole of the above script may not even be relevant, since the following doesn't work either:

document.write("<div class='posDiv' id='div"+i+"' onclick='javascript:main()' >"+textArray[i]+"</div>");