Conexion base de datos vb .net

C:\Users\grosales\Desktop\WindowsApplication1\WindowsApplication1\Form1.vb 'Conexion Base de Dates, Consulta e Ingreso de Información 'GUILLERMO ALFONSO ROSALES GOETHE 'Estudiante Ingeniería deSistemas - ITM Instituto Técnológico Metropolitano 'Medellín - Colombia '2011 Imports System.Data Public Class Form1 Dim cadena As String = "Data Source = DESARROLLO2\GUILLERMO; Initial Catalog = prueba;Integrated Security = True" Private Sub Llenar_Data_Grid() 'Método que se conecta a la base de datos y llena un gird Dim tabla As DataTable Using Cnx As New System.Data.SqlClient.SqlConnection(cadena)Using Comando As New System.Data.SqlClient.SqlCommand Cnx.Open() Comando.Connection = Cnx Comando.CommandType = CommandType.Text Comando.CommandText = "select * from vb_net;" Using Adapter As NewSystem.Data.SqlClient.SqlDataAdapter Adapter.SelectCommand = Comando tabla = New DataTable Adapter.Fill(tabla) Cnx.Close() End Using End Using End Using Me.DataGridView1.DataSource = tabla End Sub PrivateSub Insertar() 'Método que Inserta datos a La tabla con una transaccion por codigo Dim open As Boolean = False, tran As Boolean = False Using Cnx As New System.Data.SqlClient.SqlConnection(cadena)Using Comando As New System.Data.SqlClient.SqlCommand Try Cnx.Open() open = True Comando.Connection = Cnx Comando.CommandType = CommandType.StoredProcedure Comando.CommandText = "Nuevo_Usuario"Comando.Parameters.AddWithValue("@nombre", Me.txt_Nombre.Text) Comando.Parameters.AddWithValue("@cargo", Me.cbo_Cargo.SelectedValue) Comando.Parameters.AddWithValue("@comentarios", Me.txt_Comentarios.Text)Comando.Parameters.AddWithValue("@subsidiado", Me.chk.Checked) Comando.Transaction = Cnx.BeginTransaction() tran = True Comando.ExecuteNonQuery() Comando.Transaction.Commit() Cnx.Close()MessageBox.Show("Usuario Agregado con exito") Catch X As Exception MessageBox.Show(X.Message) Try If (tran) Then Comando.Transaction.Rollback() End If If (open) Then Cnx.Close() End If Catch ex As Exception...