Help me! Pretty pretty please?

okay, I'm screwed.. big time!
Next Saturday I am going to celebrate my 18th birthday.. that's not the problem as I'm really looking forward to it and all, but the thing is that I'm going to have a disco themed party.. And I have nothing to wear! absolutely no idea whatsoever about what to wear... :(

I was actually going to order a huge afro wig on the internet, but they were all sold out.. how typical is that? :(

So PLEASE.. And then I mean PRETTY PRETTY PLEASE, let me know if you have any ideas of what I can wear. if anyone has seen a disco inspired outfit in a store or something lately, please let me know... it would be aweful if I was the least disco dressed at the birthday as it is my birthday after all x)