How to open new window in full size on the browser with help of javascript

function win_open_max( URLWindow, WindowName)

{

var WinOpen;

var PararOption;

PararOption = 'status=yes,menubar=yes,scrollbars=yes,resizable=yes,toolbar=yes';

PararOption = PararOption + ',width=' + (screen.availWidth - 10).toString();

PararOption = PararOption + ',height=' + (screen.availHeight - 122).toString();

PararOption = PararOption + ',screenX=0,screenY=0,left=0,top=0';

WinOpen = window.open
( '', WindowName, PararOption );

WinOpen.location = URLWindow;

WinOpen.focus();

WinOpen.moveTo( 0, 0 );

WinOpen.resizeTo( screen.availWidth, screen.availHeight );

return WinOpen;

}