Windows 7 How to create a edit / upgrade button in visual basic 2010

hi all...

I created a student details database using service-based database.

The add button, remove button and save button work properly. I could not create a edit / upgrade button successfully.

Please, anyone help me.... say me the code to create a edit / upgrade button please...

here is my code :

ADD BUTTON:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Me.BiodanmentoBindingSource.AddNew()
NamaTextBox.Enabled = True
End Sub

REMOVE BUTTON:
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Me.BiodanmentoBindingSource.RemoveCurrent()
End Sub

SAVE BUTTON:
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Me.Validate()
Me.BiodanmentoBindingSource.EndEdit()
Me.TableAdapterManager.UpdateAll(Me.BiodanmentoDataSet)
End Sub

so how edit button????