function checkEnterPressed(event, buttonToClick, sender) {
    // does the event exist, else get it from window.event
    var evt = (event ? event : window.event);
    var evt_src;

    // Get the HTML element that generated the event (target in Netscape, srcElement in Explorer)
    if (evt.srcElement) {
        evt_src = evt.srcElement;
    } else if (evt.target) {
        evt_src = evt.target;
    }

    // Safari might return text node, so we get parent to get HTML element            
    if (evt_src.nodeType == 3) {
        evt_src = evt_src.parentNode;
    }

    // Get the keyCode from event (13 is the 'enter' key)
    var code;
    if (event.keyCode) {
        code = event.keyCode;
    } else if (event.which) {
        code = event.which;
    }

    if (code == 13) {
        if (evt_src == sender) {
            buttonToClick.click();
            return false;
        }
    }
    else {
        return true;
    }

}