Script error rollup 13

Hi All,

We have recently upgraded our system to rollup 13 and for some reason or another this script which runs onload in the opportunity page is giving an error:

function AttachOnRefreshEventToGrid(gridName, functionToCall)

{

var grid = document.getElementById(gridName);

grid.attachEvent("onrefresh", functionToCall);

//CalculateProducts

}

The error is indicating that there is a problem with attachEvent. I've been trying to figure out why however it has resulted in numerous failed attempts. Can someone kindly explain what the issue exactly is? Any help is much appreciated.

Thanks

Stefan