There's a chance i might meet them, what do i say?

I'm going to see Kasabian at the civic on Tuesday. Bloody hell! Im excited as frick! But my friends have gone to the same venue before - many times actually and they've always gotten photos with them. They've showed me them also. So im going to try and hang about and see if i can get an autograph ect. I think at that moment i might die and go to heaven. But, still - there's a possibility that they won't. Which im prepared for. Their only human. But i get butterflies just thinking of seeing them in concert. Im so excited! But if i did get a photo ect - I'd have no idea what to say to them. I know their just like me - if not a bit older (heh!) But they're only people. Just because they're famous doesn't mean that they're any different from me. But, i don't know. If this does actually happen and they come out for autographs, what do i say? Knowing me, i'd stand there like a klutz and be really quite because I'm so shy! I'd be like 'Um Hi..' Then i'd start laughing or smiling like the cheshire cat.