c# - How to select which control overlays other in Windows form application -

I am drawing a line during the runtime when the user clicks on 2 buttons and links them basically.

My code is something like this:

  line l = new line (); L.Size = New shape (# button as button 1 to width # 2) l. Location = button1. Location   
 There are overlays above the other line of control between the button and line, it only appears when there is no other control inbetweene.  
 How can I make a line at the top of other controls?  
  
 
 
 You can see the  line  (or any  control) in the z command ) can be used to fetch.  
  l.BringToFront ();