return statement in c# class File

 Here Is my class file function when it finds duplicate it shows messagebox but problem is that it does not stop by return statemtnt it also executes next queries on windows form

 

 

 

public void FindDuplicate(String sql, string message)

{

SqlDataAdapter sda = new SqlDataAdapter(sql, con);

DataTable dt = new DataTable();

sda.Fill(dt);

if (dt.Rows.Count > 0)

{

MessageBox.Show(message, "Duplicate Record", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);

return;

}

else

{

// MessageBox.Show("No Records Found","No Record Found",MessageBoxButtons.OK,MessageBoxIcon.Exclamation);

}