Algo asi

Imports System.Data

Imports System.Data.SqlClient

Partial Class _Default

Inherits System.Web.UI.Page

Dim cone As New SqlConnection("Data Source=(local);Initial Catalog=BDPersonal;Integrated Security=True")

Dim adpe As New SqlDataAdapter("select *from Empresa", cone)

Dim cmdgrabar As New SqlCommand

Dim dse As New DataSet

Private Sub cargar_drop()

adpe.Fill(dse, "Empresa")

Me.DropDownList1.DataSource = dse.Tables("Empresa")

Me.DropDownList1.DataTextField = "Nom_emp"

Me.DropDownList1.DataValueField = "Cod_emp"

Me.DataBind()

End Sub

Private Sub limpiar()

Me.txtncodigo.Text = ""

Me.txtnombre.Text = ""

Me.txtdni.Text = ""

Me.txtdirccion.Text = ""

Me.txtmail.Text = ""

End Sub

Private Sub grabar_nuevper()

cmdgrabar.Connection = cone

cmdgrabar.CommandType = CommandType.StoredProcedure

cmdgrabar.CommandText = "INS_PER"

cmdgrabar.Parameters.Add(New SqlParameter("@cp", SqlDbType.NVarChar))

cmdgrabar.Parameters.Add(New SqlParameter("@ce", SqlDbType.NVarChar))

cmdgrabar.Parameters.Add(New SqlParameter("@np", SqlDbType.NVarChar))

cmdgrabar.Parameters.Add(New SqlParameter("@dn", SqlDbType.NVarChar))

cmdgrabar.Parameters.Add(New SqlParameter("@dr", SqlDbType.NVarChar))

cmdgrabar.Parameters.Add(New SqlParameter("@mil", SqlDbType.NVarChar))

cmdgrabar.Parameters("@cp").Value = Me.txtncodigo.Text

cmdgrabar.Parameters("@ce").Value = Me.DropDownList1.SelectedValue

cmdgrabar.Parameters("@np").Value = Me.txtnombre.Text

cmdgrabar.Parameters("@dn").Value = Me.txtdni.Text

cmdgrabar.Parameters("@dr").Value = Me.txtdirccion.Text

cmdgrabar.Parameters("@mil").Value = Me.txtmail.Text

cone.Open()

cmdgrabar.ExecuteNonQuery()

cone.Close()

cmdgrabar.Parameters.Clear()

End Sub

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

Me.grabar_nuevper()

Me.limpiar()

End Sub

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

Me.cargar_drop()

End Sub

End Class