Reset password for a user in ActiveDirectory using asp.net

Private Function IsExistInAD(ByVal loginName As String) 
   Dim objUsersDE As New System.DirectoryServices.DirectoryEntry("LDAP://10.61.1.188/DC=contentlibrary,DC=dev", loginName, "P@ssw0rd", AuthenticationTypes.Secure)
        'Dim userName As String = ExtractUserName(loginName)
        Dim search As New DirectorySearcher(objUsersDE)
        search.Filter = [String].Format("(SAMAccountName={0})", loginName)
        Dim result As SearchResult = search.FindOne()
        Try
            objUsersDE.InvokeSet("setPassword", "P@ssw0rd123")
            'objUsersDE.CommitChanges()
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try