backdraft

Ok...you probably hear so many people asking the same question but I am just afraid that I'll be rejected. Homecoming is next month and I want to ask a girl out to the dance. I talk to her every once in a while and she is always nice to me. I don't know if she is interested in me or not. I am 16 and have always been afraid to ask girls out. What would be the best way to ask her out without embarrassing myself? Replies would be greatly appreciated. Thanks!