How do you move on from liking someone when?

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I liked this girl (who was my great friend) from 2009 to October 2013 and I told her I liked her but she only saw me as a friend so finally in October 2013 I started trying to move on from liking her and then earlier tonight I saw a picture of her on my Facebook news feed thing and after looking at the picture the old feelings of liking her came back so even after thinking I had moved on from liking her I guess I didn't..So my question is how can I move on from liking her when it all it takes is looking at one picture of her and I like her all over again?
If you can answer my question thanks