Newbe Question: Send Form Data in POST method

'Activity module
Sub Process_Globals
   'These global variables will be declared once when the application starts.
   'These variables can be accessed from all modules.
   
   Dim url As String
   Dim usern As String
   Dim passn As String
   Dim param As String
End Sub

Sub Globals
   'These global variables will be redeclared each time the activity is created.
   'These variables can only be accessed from this module.

   Dim UserName As EditText
   Dim Login As Button
   Dim Password As EditText
   Dim hc As HttpClient
   Dim req As HttpRequest
   
   
End Sub

Sub Activity_Create(FirstTime As Boolean)
   'Do not forget to load the layout file created with the visual designer. For example:
   Activity.LoadLayout("jsonapp")
   
   If FirstTime Then
        hc.Initialize("hc")
    End If

End Sub

Sub Activity_Resume

End Sub

Sub Activity_Pause (UserClosed As Boolean)

End Sub

Sub Login_Click
   url = "http://domain.com/jsonapp.php"
   usern = UserName.Text
   passn = Password.Text
   param = "user="& usern &"&pass="& passn
   
   req.InitializePost2(url, param.GetBytes("UTF8"))
    hc.Execute(req, 1)
   
End Sub
Sub hc_ResponseError (Reason As String, StatusCode As Int, TaskId As Int)
    Msgbox(Reason, "error")
End Sub
Sub hc_ResponseSuccess (Response As HttpResponse, TaskId As Int)
    Msgbox(Response.GetString("UTF8"), "success")
End Sub