Try this and what happend?\
vb.net Code:
  1. cmd = New OleDbCommand("Update Table1 set From_Balance= From_Balance-@Fsum where From_Bank_Name=@FBankName and  From_Account_No=@FAccountNo", con)
  2. cmd.Parameters.AddWithValue("@Fsum", TextBox1.Text)
  3. cmd.Parameters.AddWithValue("@FBankName", ComboBox1.Text)
  4. cmd.Parameters.AddWithValue("@FAccountNo", ComboBox2.Text)
  5. Dim rowseffected1 as Integer - cmd.ExecuteNonQuery()
  6. cmd2 = New OleDbCommand("Update Table1 set To_Balance= To_Balance+@Tsum where To_Bank_Name=@TBankName and  To_Account_No=@TAccountNo", con)
  7. cmd2.Parameters.AddWithValue("@Tsum", TextBox2.Text)
  8. cmd2.Parameters.AddWithValue("@TBankName", ComboBox3.Text)
  9. cmd2.Parameters.AddWithValue("@TAccountNo", ComboBox4.Text)
  10. Dim rowsaffected As Integer = cmd2.ExecuteNonQuery
  11. cmd.Dispose()
  12. cmd2.Dispose()
  13. MsgBox("Number of rows affected from first Query are: " & rowseffected1.ToString())
  14. MsgBox("Number of rows affected from second Query are: " & rowseffected.ToString())

ps Paul I tried to tell him that at least once already