function openCenteredWindow(url, height, width, name, parms){

   var left = Math.floor( (screen.width - width) / 2);
   var top = Math.floor( ((screen.height-35) - height) / 2);

   if (top < 0){
       op = 0
   }

   var winParms = "top=" + top + ",left=" + left + ",height=" + height + ",width=" + width;

   if (parms){
       winParms += "," + parms;
   }

   var win = window.open(url, name, winParms);

   if (parseInt(navigator.appVersion) >= 4){
       win.window.focus();
   }

   return win;

}

function viewImage(width,height,file){

    var sWidth, sHeight;
    var aWidth  = screen.width - 8;
    var aHeight = screen.height - 50;
    var scroll  = 'yes';

    // if the width or height exceeds the users screen dimensions alter it

    sWidth  = width;
    sHeight = height;

    

    if(aWidth < width){
        sWidth  = aWidth;
        scroll  = 'yes';
    }


    if(aHeight < height){
        sHeight = aHeight;
        scroll  = 'yes';
    }

    openCenteredWindow(file,sHeight+50,sWidth+8,'imageView','scrollbars='+scroll);

    return;

}