API Authorization Denied/HTTP POST?

[cmsplushosting]

Dim newURL As String = My.Settings.WHMCSBaseURL & "/includes/api.php"


       ' Create a request using a URL that can receive a post. 
       Dim request As WebRequest = WebRequest.Create(newURL)
       ' Set the Method property of the request to POST.
       request.Method = "POST"
       ' Create POST data and convert it to a byte array.
       Dim postData As String = "username=admin" & _
           "&password=1234" & _
           "&action=getsupportstatuses"

       Dim byteArray As Byte() = Encoding.UTF8.GetBytes(postData)
       ' Set the ContentType property of the WebRequest.
       request.ContentType = "application/x-www-form-urlencoded"
       ' Set the ContentLength property of the WebRequest.
       request.ContentLength = byteArray.Length
       ' Get the request stream.
       Dim dataStream As Stream = request.GetRequestStream()
       ' Write the data to the request stream.
       dataStream.Write(byteArray, 0, byteArray.Length)
       ' Close the Stream object.
       dataStream.Close()
       ' Get the response.
       Dim response As WebResponse = request.GetResponse()

       ' Get the stream containing content returned by the server.
       dataStream = response.GetResponseStream()
       ' Open the stream using a StreamReader for easy access.
       Dim reader As New StreamReader(dataStream)
       ' Read the content.
       Dim responseFromServer As String = reader.ReadToEnd()
       ' Display the content.
       TextBox1.Text = responseFromServer
       ' Clean up the streams.
       reader.Close()
       dataStream.Close()
       response.Close()

 

It returns:

result=error;message=Authentication Failed;