var win = null;
var LeftPosition;
var TopPosition;
var settings;
function NewWindow(mypage,myname) {
    LeftPosition = (screen.width) ? (screen.width-850)/2 : 0;
    TopPosition = (screen.height) ? (screen.height-600)/2 : 0;
    settings = 'height=470,width=600,top='+TopPosition+',left='+LeftPosition+',resizable=yes,scrollbars=yes'
    win = window.open(mypage,myname,settings)
    if(win.window.focus) {
        win.window.focus();
    }
}