URL Open window - Browser Not showing Minimize & Maximize Buttons on Full Screen?

Hi, it's my first project in asp.net, while I open the url in full screen mode, it's not showing the Minimize,Maximize& Close buttons to close the browser... So how to achieve this ?

Url="https://maps.google.com"

Page.ClientScript.RegisterStartupScript(

this.GetType(), "paramu_prg", "window.open('" + Url + "','','fullscreen=yes, left=50, top=50, height=750, width= 1124, toolbars=yes, status=yes, scroll=yes, modal=yes, maximized=yes');", true

);

Thanks for the guidances