function displayWindow(url)
{
    var newWindowLeft;
    var newWindowTop;

    newWindowLeft = (window.self.screen.availWidth / 2) - 400;
    newWindowTop = (window.self.screen.availHeight / 2) - 200;		
    window.open (url,"", "scrollbars=yes,toolbar=no,titlebar=no,location=no,left=" + newWindowLeft + ",top=" + newWindowTop + ",directories=no,status=no,menubar=no,resizable=no,width=790,height=400")
}