function PopUp (URL, X, Y, W, H, R, S, settings)
      {
      var myBrowser = navigator.appName;
      if (X ==  0) {X = (screen.availWidth-W)/2;}
      if (X == -1) {X =  0;}
      if (X == -2) {X =  screen.availWidth-W;}
      if (Y ==  0) {Y = (screen.availHeight-H)/2;}
      if (Y == -1) {Y =  0;}
      if (Y == -2) {Y =  screen.availHeight-H;}
      if (W ==  0) {W =  screen.availWidth-10;  X = 0;}                            // Full screen puts popup under calling page.
      if (H ==  0) {H =  screen.availHeight-10; Y = 0;}
      if (R ==  1) {settings = settings + ',resizable=1';}
      if (S ==  1) {settings = settings + ',scrollbars=1';}
      settings = settings + ',height=' + H + ',width=' + W;
      if (myBrowser == 'Microsoft Internet Explorer') {settings = settings + ',top=' + Y + ',left=' + X;}
      if (myBrowser == 'Netscape') {settings = settings + ', screenX=' + X + ', screenY=' + Y;}

      var w=window.open (URL, '', settings, true);
      }