Love Problem

Hey,

I like a girl alot in my office. I thought she also liked me. I mean she normally wanted to be near to me, looked at me without my knowledge. I noticed that she missed me in my absence. But suddenly I came to know that a guy regularly drops to her office. I stalked the guy's facebook and found that he keeps on writing about her. He even posts love message to her wall. She regularly likes the posts but doesn't reply anything. How would I know if she loves me or not? I am just getting crazy..I can't pay attention to anything just because of that. Please help me if I should avoid her to get her attention. I don't want to ask her because it will be more harmful to ask a girl with a boyfriend. I don't want to degrade my personality infront of her. Is there any better way to find out if she loves me? Do girls feel desperate to be near if someone they like avoid them. Can I avoid her to know if she likes me or not. Please help

SNR