HELP! HELP! Access problem to WebServices

[Farm]

I have written a generic proxy class for web services access
This proxy class runs in the same server of WebService
The class works fine if the browser runs in LAN, however it generates the following error if i access from remote machine

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Object reference not set to an instance of an object.

Description
An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details
System.NullReferenceException: Object reference not set to an instance of an object

Source Error:
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace
[NullReferenceException: Object reference not set to an instance of an object.]
Farm.Web.Controls.SoapMethod.ServerExecute(String SoapHost, String SoapServer, String SoapNameSpace, HttpRequest Request, HttpSessionState Session) in SoapMethod.vb:25
Farm.Web.Controls.ComboBox.Render(HtmlTextWriter output) in ComboBox.vb:426
System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +243
System.Web.UI.Control.RenderChildren(HtmlTextWrite r writer) +72
System.Web.UI.Control.Render(HtmlTextWriter writer) +7
System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +243
System.Web.UI.Page.ProcessRequestMain() +192
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Some server code

With HTTPRe

.Proxy = GlobalProxySelection.GetEmptyWebProxy()

.ContentType = "text/xml; charset=utf-8
.Method = "POST
.KeepAlive = Fals

.Credentials = CredentialCache.DefaultCredential

Dim i As Int3

Dim strKey As Strin

For i = 0 To Request.Headers.Count -
strKey = Request.Headers.GetKey(i
AddHeader(strKey, Request.Headers(strKey)) 'utility functio
Nex

.CookieContainer = New CookieContaine
.CookieContainer.GetCookies(curUri) 'get the list of cookies to send to the destination site

Dim app As New CookieCollectio

For i = 0 To Request.Cookies.Count -
app.Add(CastCookie(Request.Cookies.Item(i), Request.ServerVariables("HTTP_HOST"))
Nex

.CookieContainer.Add(app

End Wit

Dim strm As System.IO.StreamWrite
Dim XML As New System.Xml.XmlDocumen
Dim HttpRes As HttpWebRespons

Tr
'Write the Request Strea
error here------> strm = New StreamWriter(HTTPReq.GetRequestStream(), Encoding.UTF8
........

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The server is protected by a linux firewall without proxy

Thank you very much !

[NM]

Have you initilised HttpReq var before affecting its instances?

Dim HTTPReq as New HttpWebRequest

and then :

> With HTTPReq
>
> .Proxy = GlobalProxySelection.GetEmptyWebProxy()
>
> .ContentType = "text/xml; charset=utf-8"
> .Method = "POST"
> .KeepAlive = False
>
> .Credentials = CredentialCache.DefaultCredentials
>
> Dim i As Int32
>
> Dim strKey As String
>
> For i = 0 To Request.Headers.Count - 1
> strKey = Request.Headers.GetKey(i)
> AddHeader(strKey, Request.Headers(strKey)) 'utility

function

> Next
>
> .CookieContainer = New CookieContainer
> .CookieContainer.GetCookies(curUri) 'get the list of cookies

to send to the destination site

>
> Dim app As New CookieCollection
>
> For i = 0 To Request.Cookies.Count - 1
> app.Add(CastCookie(Request.Cookies.Item(i),

Request.ServerVariables("HTTP_HOST")))

> Next
>
> .CookieContainer.Add(app)
>
> End With
>
> Dim strm As System.IO.StreamWriter
> Dim XML As New System.Xml.XmlDocument
> Dim HttpRes As HttpWebResponse
>
> Try
> 'Write the Request Stream
> error here------> strm = New StreamWriter(HTTPReq.GetRequestStream(),

Encoding.UTF8)

> ........

[Farm]

Hi NM, I have read your answer, but it don't works

I had initialized class with this method: (the second is another way
--------------------------------------------------
HTTPReq = CType(System.Net.WebRequest.Create(curUri), HttpWebRequest
' HTTPReq = CType(System.Net.WebRequest.CreateDefault(curUri), HttpWebRequest
--------------------------------------------------

As mentioned in HttpWebRequest remarks can't be utilized the constructor "New

-------------------- From HttpWebRequest remarks ---------------------------------------------------------------------------

>Do not use the HttpWebRequest constructor. Use the WebRequest.Create method to initialize new HttpWebRequest >instances. If the scheme for the URI is http:// or [url]https://,[/url] Create returns an HttpWebRequest instance

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However Thank you very much !