Hi guys,

I need your help. I want to connect to the proxy server using with the webbrowser while reads the strings of the proxy username, password, ip and the ports in each textbox.


Here it is the code:

Code:
Imports System.Net
Imports System.IO

Public Class Form1
  Inherits System.Windows.Forms.Form

 Public Function GetHTMLPage(ByVal URL As String, Optional ByVal UseProxy As Boolean = False, Optional ByVal ProxyAddress As String = "", Optional ByVal ProxyPort As Integer = 0, Optional ByVal UserName As String = "", Optional ByVal PassWord As String = "", Optional ByVal Domain As String = "") As String

        Dim sResult As String = ""
        Try
            Dim objResponse As WebResponse
            Dim objRequest As WebRequest = System.Net.HttpWebRequest.Create(URL)

            If Not UseProxy Then
                Dim oProxy As New WebProxy(ProxyAddress, ProxyPort)
                If Domain <> "" Then
                    oProxy.Credentials = New NetworkCredential(UserName, PassWord, Domain)
                Else
                    oProxy.Credentials = New NetworkCredential(UserName, PassWord)
                End If
                objRequest.Proxy = oProxy
            End If


            objRequest.Method = "GET"
            objRequest.Timeout = 120000 ' 20 sec.
            objResponse = objRequest.GetResponse

            Dim sr As System.IO.StreamReader = New System.IO.StreamReader(objResponse.GetResponseStream(), System.Text.Encoding.UTF7)

            sResult = sr.ReadToEnd()
            sr.Close()
            ' when code-execution has reached this point without
            ' throwing an error, the html page is loaded which
            ' means all is o.k.
            MessageBox.Show("You are connected Success")
        Catch ex As System.Exception
            MessageBox.Show("You have failed connected")
        End Try
        Return sResult
    End Function

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        If GetHTMLPage("http://www.whatismyip.com" & ProxyAddress.Text & IIf(IsNumeric(ProxyPorts.Text), ProxyPorts.Text, 0), ProxyUsername.Text, ProxyPassword.Text) Is "" Then
            WebBrowser1.Url = New Uri("http://www.whatismyip.com")
        End If
    End Sub

However, I have received the error that are jumping on If GetHTMLPage statement. The error is Conversion from string "name of string" to type 'Boolean' is not valid.


I don't know what to do.


Any idea?