503 error httpwebrequest

Hi,

Here's a part of my code:

Code:

---

        For i = 0 To 1000

            Dim inum As String = i & "0"
            Dim request As System.Net.HttpWebRequest = System.Net.HttpWebRequest.Create("http://www.google.nl/search?q=inurl:" & textbox1.text & "+site:.nl&start=" & inum)
            Dim response As System.Net.HttpWebResponse = request.GetResponse

---

I get this error/warning if i debug it

Code:

---

Webexception was unhandled
The remote server returned an error: (503) Server Unavailable.

---

What's wrong at my code?

at textbox1.text you just fill in like "test" or something. ( without ")

I'm using Visual Basic 2010

Gateway timeout 503 (TO BE DISCUSSED)

This is equivalent to Internal Error 500, but in the case of a server which is in turn accessing some other service, this indicates that the respose from the other service did not return within a time that the gateway was prepared to wait. As from the point of view of the clientand the HTTP transaction the other service is hidden within the server, this maybe treated identically to Internal error 500, but has more diagnostic value.