onerror = handleErr
var txt ;

function handleErr(msg, url, l)
{
    txt = "There was an error on this page.\n\n" ;
    txt += "Error: " + msg + "\n" ;
    txt += "URL: " + url + "\n" ;
    txt += "Line: " + l + "\n\n" ;
    txt += "Click OK to continue.\n\n" ;
    alert(txt) ;

    return true ;
}