JS only pops up a center pop-up window

Var newwindow;//defines a window that facilitates communication between Windows
function Makenewwindow (URL) {
   if (!newwindow | | newwindow.closed) {
        var width =;
        var height = 300;
        var left = parseint ((SCREEN.AVAILWIDTH/2)-(WIDTH/2));//center screen
         var top = parseint ((SCREEN.AVAILHEIGHT/2)-(HEIGHT/2));
        var windowfeatures = "Width=" + width + ", height=" + height + ", Status,resi Zable,left= "+ Left +", top= "+ Top +" screenx= "+ Left +", screeny= "+ top;
        newwindow = window.open (URL, "Subwind", windowfeatures);
   } else {
       //window is already open, so bring it to th E Front
        newwindow.focus ();
   }
}

window.open the command that pops up the new window;
page.html the filename of the popup window;
NewWindow the name of the pop-up window (not the file name), non-required, available empty ' ' instead;
height=100 window height;
width=400 window width;
The pixel value of the Top=0 window from the top of the screen;
The pixel value of the left=0 window from the left side of the screen;
Toolbar=no whether the toolbar is displayed, yes is displayed;
Menubar,scrollbars represents the menu bar and scroll bar.
Resizable=no whether the window size is allowed to change, yes is allowed;
Location=no whether the address bar is displayed, yes is allowed;
Status=no whether the information in the status bar is displayed (usually the file is already open), yes is allowed;

JS only pops up a center pop-up window