Updating Retrieved Records SQL Problem

Hello,

I am retriving records on a page, I am able to make changes cuase the data is displayed in textboxes, my question is how to save the changes I made in the database.

 Also in my below code for retriving the data what statement do I need to add so that I can use a QuerryString to filter the results. ex (default.aspx?CID=1) and only records that

match that would display.

Here is my code: for retriving data

Private Sub displayrecord()
SqlConnection1.Open()
        Dim SqlDataAdapter1 As New SqlDataAdapter("SELECT * FROM table1", SqlConnection1)
        Dim objReader As SqlDataReader
        Dim SqlCommand1 As New SqlCommand("SELECT * FROM table1", SqlConnection1)
        SqlDataAdapter1.Fill(dsMember)
        objReader = SqlCommand1.ExecuteReader()

        objReader.Read()
        txtbox_confirmpass.Text = objReader("MemberPassword")
        txtbox_name.Text = objReader("MemberName")
        txtbox_birthdate.Text = objReader("MemberDOB")
        txtbox_email.Text = objReader("MemberEmail")
        Dropdown_Gender.SelectedValue = objReader("Gender")
             objReader.Close()
        SqlConnection1.Close()
    End Sub
Private Sub btnUpdate_Click