blackberry - How to display Half screen? -

i working on project need display listfield takes top half of screen when user clicks on menu item. should display on top of earlier screen. how can implement it?

here ideas:

1. use listfield directly above screen size required screen.
2. use popupscreen listfield
3. use screensplit functionality display half of screen

popupscreen best fit question. can try , post code didn't work?

another option use managers split screen (higher manager , lower manager) , hold 2 managers: 1 displayed on click , 1 used pointer displayed manager. then, when ever replace event fired should call following function:

void updatemanagers(boolean click)     {       if(click)   {         currentmanager = afterclickmanager;       }       else       {       currrentmanager = beforeclickmanager;       }       invalidate();   } 

where currentmanager instance of manager , afterclickmanager & beforeclickmanager instances of class extends manager (no need same class).

note should add currentmanager screen layout before using invalidate function.