.Net test URL is valid?

We have a form on our website that asks customers to enter their website address.

I currently have the code below which checks that their URL is alive.

The code works most of the time. However I recently saw it failed a URL giving the exception Permanently Moved (302) even though entering the URL in a browser address bar worked.

The URL entered on the form was tentworld.com.au

Is there a way to return that such sites URL's are OK?

   Private Function fCheckUrlIsOK(strURL As String) As Boolean

    strURL = strURL.Trim.ToLower

    'Prefix http if not there already
    If Left(strURL, 7) = "http://" Or
       Left(strURL, 8) = "https://" Then

    Else
        strURL = "http://" + strURL
    End If

    Try
        Dim request1 As HttpWebRequest = WebRequest.CreateHttp(strURL)
        With request1
            .Timeout = 10000 '10 seconds
        End With

        Dim response1 As WebResponse = request1.GetResponse()

    Catch ex As Exception

        'Uncomment to see exception
        'fErrorRecord(ex)

        Return False

    End Try

    Return True

End Function

I did the following and it worked:

  Private Function fCheckURLIsOK(strURL As String) As Boolean

    Dim strURLCleaned As String = strURL.ToLower.Trim
    Dim strURLNew As String = ""

    'Remove prefixes
    strURLCleaned = strURLCleaned.Replace("https://www.", "")
    strURLCleaned = strURLCleaned.Replace("https://", "")
    strURLCleaned = strURLCleaned.Replace("http://www.", "")
    strURLCleaned = strURLCleaned.Replace("http://", "")

    'Try 1
    strURLNew = "https://www." + strURLCleaned
    If fCheckUrlIsOKIndividual(strURLNew) = True Then
        Return True
    End If

    'Try 2
    strURLNew = "https://" + strURLCleaned
    If fCheckUrlIsOKIndividual(strURLNew) = True Then
        Return True
    End If

    'Try 3
    strURLNew = "http://www." + strURLCleaned
    If fCheckUrlIsOKIndividual(strURLNew) = True Then
        Return True
    End If

    'Try 4
    strURLNew = "http://" + strURLCleaned
    If fCheckUrlIsOKIndividual(strURLNew) = True Then
        Return True
    End If

    Return False

End Function

Private Function fCheckUrlIsOKIndividual(strURL As String) As Boolean

    Try
        Dim request1 As HttpWebRequest = WebRequest.CreateHttp(strURL)
        With request1
            .Timeout = 10000 '10 seconds
        End With

        Dim response1 As WebResponse = request1.GetResponse()

    Catch ex As Exception

        'Uncomment to see exception
        'fErrorRecord(ex)            

        Return False

    End Try

    Return True

End Function

Note that I also added some headers to help normalize the request. Without those the particular server didn't allow the request.