Problema creando archivo .txt

[lisseth]

gracias por respoder, ya solucione el problema de la siguiente forma:

Dim strStreamWriter As StreamWriter

Dim strStreamW As Stream

Dim FilePath As String = "Archivo.txt"

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim filename As String = Server.MapPath("~/mensaje/errores/" + FilePath)

try

strStreamW = File.OpenWrite(filename)

strStreamWriter = New StreamWriter(strStreamW, System.Text.Encoding.UTF8)

Catch ex As Exception
Me.Label3.Text = "Error" + ex.Message

Finally
strStreamWriter.Close()
strStreamW.Close()
End Try

Solo puse los .close dentro del finally y ya no me dice que no puedo usarlo ni nada de eso, gracias!!!