WiseJ.onException question

I am trapping the invalidSession so that I can automatically refresh the page.  I am doing this so that when I do an application update, the app will automatically reload.

When the error is not an invalid session, how to get the wiseJ error message to show??

Wisej.onException = function (ex) {
if (ex.invalidSession) {
document.getElementById(‘pnlReloading’).style.display = ”;
var tid = setTimeout(Reloading, 5000);
}
else {
//how to get the wiseJ error message to show??

}
}

Thanks, Shawn