function openWindowNS (url ,name, width, height) {
   leftPosition = (screen.width-width)/2;
   topPosition = (screen.height-height)/2;
   winprops = 'width='+ width +',height='+ height +',left='+leftPosition +',top='+topPosition +', toolbar=no,titlebar=no,statusbar=no,locationbar=no,resizable=no,scrollbars=no'
   wnd = window.open (url, 'name', winprops)
   wnd.focus()
}