Pop up window

can we create a pop up window inside a window.

i am making a scrollable horizontal list with touches enabled (basically its a window) and on click of buttons inside it ,i want a pop up window with more buttons inside it.

i am doing it with GUI.window() function but it doesn't seem to work.

 window1Rect=new Rect(window1Margin.x,window1Margin.y,Screen.width-(2*window1Margin.x),Screen.height-(window1Margin.y+(Screen.height-windowMargin.y)));
         
         if(doWindow0)
             {
                 GUI.Window(1,window1Rect,(GUI.WindowFunction)DoWindow0," Pop Up window ");
             }

this code ios written inside a window which has swipe enabled .

any idea how this needs to be implemented... what's wrong with the code...???