proxy pass values to website

trying to include the proxy but does not work

Imports System.Collections.Generic
Imports System.Linq
Imports System.Web
Imports System.Data
Imports System.Configuration
Imports System.Xml.Linq
Imports System.Net
Imports System.Net.Mail
Imports System.Data.SqlClient
Imports System.IO
Imports System.Globalization

'''

''' Summary description for smsapi
'''

Public Class smsapi

Public Function SendEnglishSMS(ByVal mobilno As String, ByVal msgcontent As String) As Boolean


Dim res As String = String.Empty
Try

res = apicall("http://............................................")
Catch ex As Exception
End Try


If Not res.StartsWith("Wrong Username or Password") Then

Return True
Else
'message not sent successfully................
Return False
End If

End Function

Public Function apicall(ByVal url As String) As String


Dim httpreq As HttpWebRequest = DirectCast(WebRequest.Create(url), HttpWebRequest)
Try

Dim myProxy As New Net.WebProxy("ip address", 80)
myProxy.BypassProxyOnLocal = True
myProxy.Credentials = New NetworkCredential("username", "password")
httpreq.Proxy = myProxy


Dim httpres As HttpWebResponse = DirectCast(httpreq.GetResponse(), HttpWebResponse)

Dim sr As New StreamReader(httpres.GetResponseStream())




Dim results As String = sr.ReadToEnd()
sr.Close()
Return results
Catch ex As Exception
Return "0"
End Try

End Function
End Class