Open Data Reader Associated with the command

Question

Int64 amnt = Convert.ToInt64(TextBox1.Text);

int dur = Convert.ToInt16(DropDownList1.SelectedItem.Text);

int intr=5;

switch (dur)

{

case 1:

intr = 5;

break;

case 2:

intr = 7;

break;

case 3:

intr = 9;

break;

}

SqlConnection scn = new SqlConnection(@"Data Source=SRIKANTH\MYNEWSQL;Initial Catalog=OnlineBankingServer;Integrated Security=true;");

SqlCommand cmd = new SqlCommand();

SqlDataReader dr;

try

{

scn.Open();

cmd.Connection = scn;

cmd.CommandText = "select accnt_bal from Cust_Details where account_num=" + uid;

dr = cmd.ExecuteReader();

string invok = "no";

while (dr.Read())

{

if (Convert.ToInt64(dr["accnt_bal"]) > amnt)

invok = "yes";

}

dr.Close();

if (invok == "yes")

{

TransactionNumberGenerator tr = new TransactionNumberGenerator();

Int64 invnum = tr.fxdinvgen();

cmd.CommandText = "select Inv_Id from Fixd_Inv where account_num=" + uid + " and act='yes'";

dr = cmd.ExecuteReader();

while (dr.Read())

{

if (Convert.ToInt64(dr["Inv_Id"]) == invnum)

invnum = tr.fxdinvgen();

}

dr.Close();

cmd.CommandText = "insert into Fixd_Inv values(" + uid + "," + invnum + "," + amnt + "," + intr + "," + dur +",DATEADD(yyyy,"+dur+",CURRENT_TIMESTAMP),'yes')";

cmd.ExecuteReader();

dr.Close();

Int64 tid = tr.transact_gen();

cmd.CommandText = "select tid from Transactions where account_num=" + uid;

dr = cmd.ExecuteReader();

while (dr.Read())

{

if (Convert.ToInt64(dr["tid"]) == tid)

tid = tr.transact_gen();

}

dr.Close();

cmd.CommandText = "insert into Transactions values(" + uid + "," + tid + ",'finv'" + amnt + ",CURRENT_TIMESTAMP)";

cmd.ExecuteNonQuery();

Label1.ForeColor = Color.Green;

Label1.Text = "Amount Invested Successful, Your Investment Number is : " + invnum;

}

else

{

Label1.ForeColor = Color.Red;

Label1.Text = "Insufficient amount in your account";

}

}

catch (Exception ex)

{

Label1.ForeColor = Color.OrangeRed;

Label1.Text = ex.Message;

}

}

}

 

 

 

I wrote this code but i am getting an error
There is a datareader opened associated with this command which must be closed first