Visual Basic

Private Sub txt1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txt1.KeyPress
        Try
            If Not (Char.IsNumber(e.KeyChar) Or Char.IsControl(e.KeyChar)) Then e.Handled = True
        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try
    End Sub

Dim Save_4 As String = "insert into itemmst (itm_description) values (@itm_description)"
Dim com As SqlCommand = New SqlCommand(Save_4, con)

Dim par As SqlParameter = New SqlParameter("itm_description", SqlDbType.Text, 255, ParameterDirection.Input, False, 0, 0, "itm_description", DataRowVersion.Current, itm_description)
com.Parameters.Add(par)

con.Open()

Dim Trans As SqlTransaction
Trans = con.BeginTransaction
com.Transaction = Trans

Try
    com.ExecuteNonQuery()
    Trans.Commit()

Catch ex As Exception
    If Not Trans Is Nothing Then
        Trans.Rollback()
    End If
    MsgBox(ex.Message)
End Try

con.Close()

Dim dataStorage As String

Private Sub SystemRepliedEventHandler(ByVal data As String) Handles tcpSend.SystemReplied

    'MsgBox(data)
    'create the controls to display data
    'this doesn't work
    'Dim type As New TextBox
    'type.Location = New Point(100, 100)
    'type.Size = New Size(100, 100)
    'type.Text = data
    'Controls.Add(type)

    dataStorage = data
    Invoke(New MethodInvoker(AddressOf MyAddControl))

End Sub

Private Sub MyAddControl()

    Dim type As New TextBox
    type.Location = New Point(100, 100)
    type.Size = New Size(100, 100)
    type.Text = dataStorage
    Controls.Add(type)

End Sub

Private Sub SystemRepliedEventHandler(ByVal data As String) Handles tcpSend.SystemReplied

    dataStorage = data
    If (InvokeRequired) Then
        Invoke(New MethodInvoker(AddressOf MyAddControl))
    Else
        MyAddControl()
    End If

End Sub