hey, depends on what's in the panel, you can either change the bmap, or if you have a seperate panel, just make the old one invisible and the new on visible

Code:
void main(){
  while(!key_enter){wait(1);} //wait until the enter key is pressed
  pnl_this.bmap = new_bmp; //show new bmap
}
or
Code:
void main(){
  while(!key_enter){wait(1);} //wait until the enter key is pressed
  reset(pnl_old, SHOW); //hide previous panel
  set(pnl_new, SHOW); //show new panel
}

hope this helps