JS how to close the current page without popping up the prompt box

Close the current page and open a new page (without prompting)

function closewinandopen (URL) {

  // using random number processing Winname

   var swinname = "LR" +parseint (Math.random () * 100000000);

window.open (Url,swinname, ' Toolbar=no,location=no,directories=no,status=yes,menubar=no,scrollbars=no, Resizable=yes,copyhistory=yes ');     Closewin ();}

Close the current page

function Closewin () {    Window.opener=null;    window.open (', ' _self ');    Window.close ();}

Close Parent page:

Response.Write ("<script>window.top.opener=null;window.parent.close ();</script>")

(Window.top.close () to make)

setting Window.opener=null can not be displayed: "The page you are viewing is trying to close the window, whether to close the window"

JS how to close the current page without popping up the prompt box