how to use itemcommand w/datalist & buttons w/out object reference error?

i'm in c# ASP.NET and I'm new to all this. trying to teach myself but I'm hung up on something that I suppose should be simple. I couldn't find the answer on here with searches because I guess I don't know the appropriate way to describe what I'm looking for. So i last resorted to bugging you guys for an answer.i'm in c# ASP.NET and I'm new to all this. tryi