function popUp( url )
{
    var properties;
    properties = "toolbar=no, menubar=no, directories=no, status=no, scrollbars=yes, resizable=no, copyhistory=yes, width=800, height=600, ";
    properties += "top="+(window.screen.height-600)/2+", ";
    properties += "left="+(window.screen.width-800)/2;
    window.open( url, '_blank', properties );
}

function hidePopUpLayer()
{
    window.getElementById('popUpLayer').style.display = 'none';
}