var win = null;
        function NewWindow(mypage,myname,scroll){
            img = new Image();
            img.src = mypage;
            w = img.width; //Ancho;
            h = img.height; //Alto;
            LeftPosition = (screen.width) ? (screen.width-w)/2 : 0;
            TopPosition = (screen.height) ? (screen.height-h)/2 : 0;
            settings = 'height='+h+',width='+w+',top='+TopPosition+',left='+LeftPosition+',
                        scrollbars='+scroll+',resizable';
            win = window.open(mypage,myname,settings)
            if(win.window.focus){win.window.focus();}
        }