初學者做網站

if (TextBox2.Text == "")

{
Label1.Text = "※請輸入帳號";
}
else
{
SqlConnection conn = new SqlConnection("Data Source=.;Initial Catalog=mydata;User Id=sa;Password=1234");
conn.Open();

SqlCommand bb = new SqlCommand("Select * From Member_Detail Where Account_Name='" + TextBox2.Text + "'", conn);
SqlDataReader ha = bb.ExecuteReader();
if (ha.Read())
{

Label1.Text = "※請換一個";
}
else
{
Label1.Text = "OK!";
}
bb.Dispose();
ha.Dispose();
conn.Close();
conn.Dispose();
}