I write a VB 2010 program as the following. I hope to open an existed part file by this program automatically. However, I always get an error message. Can anyone help me to check where this program is wrong. Thank you very much.

Imports SolidWorks.Interop.sldworks

Imports SolidWorks.Interop.swconst

Public Class Form1

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

Dim swapp As New SldWorks

Dim model As ModelDoc2

swapp.Visible = True

model = swapp.OpenDoc6("D:\samples\part.SLDPRT", 1, 0, "", 0, 0)

End Sub

End Class