encryption rijndael using vb.net

Here's what I read when I read your post. 'My class has asked me to do something, but I am lazy, so please send me the project, along with detailed documentation so that I can pretend to have done it myself'. I don't care how bad your English is, but I am very offended that you think we'd accept a project from you, and do your entire homework, because you're lazy. Rethink your approach, or drop out of your course, because your attitude is the opposite of what is needed for someone to write software.

If you bothered to type your question in to google, there's a rijndael class built in to VB.NET, so unless your teacher is asking you to rewrite it, this is trivial to create, in any case.