How to forget her

I saw a girl only few times and talked only few times and she is my sisters hostel roomate.i only last saw her only 6 months ago.but iam very much attracted to her,but I know that it wouldnt work out between us.she doesnt know about my feeling(,but my sister knows,to whom I told to keep it a secret).please help me some tips to forget her.....

To forget this girl just try do some other stuff which will occupy your mind.think you will get someone better.throw away things which makes you think about her.best of luck man....