JAVASCRIPT - DevExpress - ASPxButton - Client Event

Question

Hi,

Can anyone see why this code block wont execute?

I am using DevExpress v 9.2.9, VS2008

If I change the top function to an Alert it runs. However, If I chop the bottom block to an Alert, nothing happens. Its as if nothing is getting sent to my second function. I can't for the life of me get Firebug or any JS debugger tools to seem to understand these damned popup controls I have to work with so I find debugging this sort of thing is taking a good 80% of my time :(

Any help appreciated.

var rowIndex = -1; 

function(s, e) {
    rowIndex = e.visibleIndex;
    gvcomponentadditions.GetRowValues(e.visibleIndex, "CUSTOMADD", OnCallback);
}
function OnCallback(value)
{
    if (value)
    {
       if (confirm('Are you sure you want to Remove this Component?'))
           callbackpaneladdremovecomponent.PerformCallback("remAddition");
    }
    else
        alert("You cannot remove this item");
}