Execute SSIS package on vb.net

Hi All,

I would like to write a small application for execute a SSIS package manually, but i got a error message as following:

Coding:
Dim oPkg As DTS.Package2
oPkg = New DTS.Package2

'Error Message Here
oPkg.LoadFromSQLServer("SQL2005", "sa", "abc", DTS.DTSSQLServerStorageFlags.DTSSQLStgFlag_Default, Nothing, Nothing, Nothing, "AccessImport")

oPkg.Execute()
oPkg.UnInitialize()

oPkg = Nothing

Error Message:
The specified DTS Package ('Name='AccessImport';ID.VersionID = {[not specified]}.{[not specified]}') does not exist.

So what is the problem here
Thank a lot.

Laputa