I want to insert the Date into SQL that is entered in textbox, When i enter 18/07/2011 it is successfully converted to DateTime object ( WORKING CODE - BELOW) , but when I enter 18/7/2011 it is not converted to DateTime object. What should I do?? if the user enters the date in the format 18/7/2011??

Code:
Imports System.Globalization
Imports System.Data.SqlClient
Imports System.Data

Partial Class _Default
    Inherits System.Web.UI.Page
    Dim con As New SqlConnection("Data source = SONIA-PC;Initial Catalog=master;Integrated Security=true")
    Dim cmd As New SqlCommand
    Dim ds As DataSet
    Dim da As SqlDataAdapter
    Dim query As String


    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Try
            query = "Insert into Practise2 values(@DOB)"
            cmd = New SqlCommand(query, con)

            Dim dt As DateTime
            If DateTime.TryParseExact(txtDateofBirth.Text, "dd/MM/yyyy", CultureInfo.InstalledUICulture, DateTimeStyles.None, dt) Then
                MsgBox(dt.ToString)
                MsgBox(dt.ToString(" yyyy-MM-dd"))
                cmd.Parameters.AddWithValue("@DOB", dt.ToString((" yyyy-MM-dd")))
            End If
            If con.State = ConnectionState.Closed Then
                con.Open()
            End If
            cmd.ExecuteNonQuery()
        Catch ex As Exception
            MsgBox(ex.Message)
        Finally
            If con.State = ConnectionState.Open Then
                con.Close()
            End If
        End Try

    End Sub

    
End Class