Disable Alt+F4 and Esc in VB.net application

Question

i am using global function to disable alt+F4 and Esc

 

Esc is working but alt is not working. pls help

 

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)

{

if (keyData == Keys.Escape)

{

MessageBox.Show("sorry you cannot close this form via Esc!!!");

return true;

}

else if (keyData == Keys.Alt)

{

MessageBox.Show("sorry you cannot close this form via Esc!!!");

return true;

}

return base.ProcessCmdKey(ref msg, keyData);

}