Adding a new record to an sql database and retrieving data

I have a form with plenty of textboxes and a button. When the button is clicked the information from the textboxes is added to a table within my sql database. I can manage to insert the data fine but I'm having trouble trying to achieve one thing...

I have 4 columns in my table, one called IDNumber, Name, Age, Address.
The information for name, age and address is from the textboxes in my form and is inserted when the user clicks the button. IDNumber is an int set to identity specification = yes, so when a record is added the number is incremented by 1.

I wish to show the user the IDNumber for the record they have just inserted, how could I achieve that? I would like to be able to achieve this with in the same button press event as the information is uploaded to the database the IDNumber is then shown on the form.

Here's the code I have so far...

Dim con As New SqlClient.SqlConnection(Connection)
        Dim cmdstr As String = "INSERT INTO testTBL(name, age, address) VALUES (@name, @age, @address)"
        Dim cmd As New SqlClient.SqlCommand(cmdstr, con)
        With cmd.Parameters
            .Add(New SqlClient.SqlParameter("@Name", name.Text))
            .Add(New SqlClient.SqlParameter("@age", age.Text))
            .Add(New SqlClient.SqlParameter("@address", address.Text))
        End With
        con.Open()
        cmd.ExecuteNonQuery()
        con.Close()