i want to show a message box after insertion of data in windows forms in c#

i want to show a message box after insertion of data in windows forms in c#

i want to use it in windows forms. int count = cmd2.ExecuteNonQuery();
if (count > 0)
{
MessageBox.Show("Policy details Entered Successfully");
clear();
}
else
MessageBox.Show("Details Not Entered");
con.Close();
I had used it in webforms but it is not working in windows form.How to
solve it.