Excuse me. I am a new vb programming and my enlish is not well. A link on top is my sample project. I have to try hard to fix it. But i have no idea how to fix. If you download my project and run it. When you press button TEST you will see the error. Please help me and expand me how to fix. I use visual studio 2010 to create project.
Edited by winki: chenge link title and add more details