how can i solve my error ??

I have two textbox  txtEmployeeID is for userName and txtPIN for password,onclick of submit button execute the following code. In my user table usr_vch_Name field is for userId and usr_vch_Password holds tha password

                bool blnFound = false;
                SqlConnection sqlCon = null;
                Array arrOptions;
                int intIndex = 0;

                sqlCon = new SqlConnection(ConfigurationManager.AppSettings["con"].ToString());//fetching the connection                      string from web.config.

                sqlCon.Open();
                SqlCommand cmd = new SqlCommand("select * from Users where usr_int_Type=1 or usr_int_Type=3 ", sqlCon);
                SqlDataReader dr = cmd.ExecuteReader();
                while (dr.Read())
                {

                    if (dr["usr_vch_Name"].ToString() == txtEmployeeID.Text)
                    {
                        if (dr["usr_vch_Password"].ToString() == txtPIN.Text)
                        {
                            blnFound = true;
                           
                            // SUCCESSFULLY USER VALIDATED

                           
                        }
                    }

                }
                if (!blnFound)
                MessageBox.Show("Wrong login info is provided");
                txtEmployeeID.Text = "";
                txtPIN.Text = "";
                dr.Close();
                sqlCon.Close();