a problem in sql update via .net

[rockers123]

hi. now im currently developing an application as my semester project and i strucked becuse of an small error. i have tried to update a record set in the sql server 2005 databse table by giving the following code. but its not showing any errors its working and displaying a message succeeded. but in database table i cant find any changes. pls help me........

my advance thanks for those who viewing my thread.

Public Shared ReadOnly SQLConnectionString As String = "Server=RUSHAN\SQLEXPRESS;Database=nolimit;Trusted_Connection=True;"
    
Dim cnn As SqlClient.SqlConnection
Dim cmd As SqlClient.SqlCommand
Dim bc As SqlClient.SqlDataAdapter
Dim dr As SqlClient.SqlDataReader
 
Private Sub cus_mod_btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cus_mod_btn.Click
        Dim sql2 As String = "UPDATE customer SET name='" & cus_mod_nme.Text & "', address='" & cus_mod_add.Text & "' ,contact='" & cus_mod_con.Text & "' WHERE (id='" & cus_mod_id.SelectedIndex & "') "
        cnn = New SqlClient.SqlConnection(SQLConnectionString)
 
        'cnn = New SqlClient.SqlConnection(SQLConnectionString)
        cnn.Open()
 
        cmd = New SqlClient.SqlCommand(sql2, cnn)
 
        cmd.ExecuteNonQuery()
        MsgBox("Records affected")
        cnn.Close()
    End Sub