function WebForm_FireDefaultButton(event, target) 
{
    var element = event.target || event.srcElement;
    if ((event.keyCode == 13) && !(element && (element.tagName.toLowerCase() == "textarea"))) 
    {
        var defaultButton = document.getElementById(target);
        if (defaultButton && typeof(defaultButton.click) != "undefined") 
        {
            __defaultFired = true;
            defaultButton.click();
            event.cancelBubble = true;
            if (event.stopPropagation) 
                event.stopPropagation();
            return false;
        }
    }
    return true;
}