Can anyone help my code for updating is given an error that “no value given for one or more required parameter".
my code is below

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim a As Integer
a = period.Text
If period.Text >= 0 Then
period.Text = period.Text - 1

OleDbConnection1.Open()

OleDbDataAdapter1.UpdateCommand.Connection = OleDbConnection1
OleDbDataAdapter1.UpdateCommand.CommandText = "Update ok set nastaff = '" & nastaff.Text & "' , period = '" & period.Text & _
"', amount = '" & amount.Text & "', groupid = " & txtid.SelectionLength + 1 & " where Period = '" & TmpNumber & "'"

'GroupCmbo.Hide()

Try
OleDbDataAdapter1.UpdateCommand.ExecuteNonQuery()
DataSet11.Clear()
OleDbDataAdapter1.Fill(DataSet11, "ok")
Catch Ex As Exception
MsgBox(Ex.Message)
End Try
OleDbConnection1.Close()

nastaff.ReadOnly = True
amount.ReadOnly = True
loan.ReadOnly = True
period.ReadOnly = True


'UpdateBtn.Enabled = False
'UpdateBtn.Enabled = True
TmpNumber = period.Text
nastaff.Focus()

Else
TextBox1.Text = 1


End If


End Sub