var popup;
function openResizableWindow(w, h, url, name)
{
    LeftPosition = (screen.width) ? (screen.width-w)/2 : 0;
    TopPosition = (screen.height) ? (screen.height-h)/2 : 0;
    var settings = 'height='+h+',width='+w+',top='+TopPosition+',left='+LeftPosition+',scrollbars=yes, resizable';
    openPopupWindow(url, name, settings);
}
function openNoResizableWindow(w, h, url, name)
{
    LeftPosition = (screen.width) ? (screen.width-w)/2 : 0;
    TopPosition = (screen.height) ? (screen.height-h)/2 : 0;
    var settings = 'height='+h+',width='+w+',top='+TopPosition+',left='+LeftPosition+',scrollbars=no, noresizable';
    openPopupWindow(url, name, settings);
}
function openPopupWindow(url, name, settings)
{
    if(popup != null)
    {
        popup.close();
    }
    popup = window.open(url, name, settings);
}