[DotNetDevelopment] Syntax to consume Web Service

[RGF]

Hello,
I am attempting to use the following web service:

http://www.vocalico.com/VocalicoWAPI.asmx?op=GetCampaingData

What is the proper syntax to consume the above web service using HTTP
POST or HTTP GET ?

I tired the following without much luck:

        Dim oWeb As New System.Net.WebClient()

        oWeb.Headers.Add("Content-Type", "application/x-www-form-
urlencoded")

        Dim bytArguments As Byte() =
System.Text.Encoding.ASCII.GetBytes("/GetCampaingData?
StartDate=7-7-2011&EndDate=7-8-2011&StartTime=800&EndTime=1300&SendEmails=False&EmailAdresses=&SendPhoneCalls=True&SendTextMsg=False&TelephoneNumbers=1234567890&User=<Private
User>&WebServiceKey=<Private Key>&Title=Web service test&Message=This
is a test of the web service&Language=English&Confirmation=No")

       Dim bytRetData As Byte() = oWeb.UploadData("http://
www.vocalico.com/VocalicoWAPI.asmx", "POST",
       bytArguments)

 
Console.Write(System.Text.Encoding.ASCII.GetString(bytRetData))


Thanks!
-r