Find email from LDAP

Imports System.DirectoryServices
Sub GetEmailAddress()
Dim EMailAddress As String = String.Empty
Dim Root As New DirectoryEntry("LDAP://RootDSE")
Dim DomainNC As String = Root.Properties("defaultNamingContext").Value
Root = New DirectoryEntry("LDAP://" & DomainNC)
Dim Searcher As New DirectorySearcher(Root)
With Searcher
.Filter = "(sAMAccountName=" & Environment.UserName & ")"
.SearchScope = SearchScope.Subtree
.PropertiesToLoad.Add("mail")
End With
Dim Result As SearchResult = Searcher.FindOne
If Not Result Is Nothing Then
EMailAddress = Result.GetDirectoryEntry.Properties("mail").Value
End If
txtRequestorName.Text = Environment.UserName.ToString()
txtEmail.Text = EMailAddress
End Sub