Ticket Booking System: Comparing two strings

Okay so I'm basically trying to verify whether the username being entered is a duplicate but there's a problem in the string comparison inside the while loop

I tried using a temp label to verify that the values are being extracted correctly.

    protected void BtnConfirmSignup_Click(object sender, EventArgs e)
    {
        int f = 0;

        SqlConnection con = new SqlConnection("Data Source=(localdb)\\MSSQLlocalDB;Initial Catalog=traveller;Integrated Security=True;Pooling=False");
        SqlCommand cmd;
        SqlDataReader read;
        /*DEBUG: Prevent duplicate usernames*/
        try
        {
            Session["user"] = TxtUsrName.Text;
            Session["pass"] = TxtPsswd.Text;
            Session["email"] = TxtEmail.Text;
            //Label6.Text = "Faf";
            //  if ((Label6.Text).Equals(TxtUsrName.Text))
            //{
            //  Label6.Text = "dafuqqqq";
            //}
            //{
            //  Label6.Text = "wtf";
         //   Label6.Text = TxtUsrName.Text;
            //}
            cmd = new SqlCommand("select Name from Useriden", con);
            con.Open();
            read = cmd.ExecuteReader();
            while (read.Read())
            {
                Label6.Text = read["Name"].ToString();
                Label1.Text = "aaa";
                //Label6.Text = "Faf";
                if ((Label6.Text).Equals(TxtUsrName.Text))
                {

                    f = 1;
                    //Label6.Text = "Duplicate Username";
                    break;

                }
            }
            if (f == 1)
            {
                Label6.Text = "Duplicate Username";
            }
            else if (f == 0)
            {
                Response.Redirect("SignUpNext.aspx");
            }
        }
        catch (Exception ex) {
            LabelUserName.Visible = true;
            LabelUserName.Text = ex.Message;
            con.Close();
            ViewState["Caption"]=ex.Message;


        }



            }

Expected: I'm entering a duplicate name so it should the change the text of the label to Duplicate Username but it instead navigates to the next page/The value of f never changes.