Windows Forms Application overlayed other Application

My WFA has overlayed other application since i added this code unto it. But i need this code to lock other users from repositioning the form. Please help ??

protected override void WndProc(ref Message m)
{
const int WM_NCLBUTTONDOWN = 161;
const int WM_SYSCOMMAND = 274;
const int HTCAPTION = 2;
const int SC_MOVE = 61456;
if ((m.Msg == WM_NCLBUTTONDOWN)&&
(m.WParam.ToInt32() == SC_MOVE))
{
return;
}
if ((m.Msg == WM_NCLBUTTONDOWN) &&
(m.WParam.ToInt32() == HTCAPTION))
{
return;
}
base.WndProc(ref m);