How can i get him to like me?

i turned 15 this year, and i never had a 'real' boyfriend. just like hook ups and stuff. but i actually really do like this one boy. we've never 'hooked up' or anything. hes one grade ahead of me. and i sat next to him in algebra all of 2nd semester. at first we just kinda talked like friends would and just kinda laugh at whatever. but then as the year was getting closer to the end (like two months before) i started liking him more and more. i knew he had recently broken up with his girl friend because she had cheated on him at a party. but anyways, he would always talk to me and sometimes when i was walking down to algebra he would come up from behinde me and call me a new nick name everyday. i thought it was cute. then things were getting better and better. like he would start more conversations and i would always ask him to throw away my papers for me and he would say 'your such a lazy a$$' and smile really cute at me. and i liked it alot. then another time me and him were talking the whole entire class time and he would like grab my wrist and say 'you have such tiny wrists!' and i would grab his and say 'you have such big wrists!' and these girls in front of me and him would always hit eachother, so one day out of no where he lightly hit me and smiled. but then i think i started liking him too much because i would purposly walk really slow to let him catch up to me, and it worked. ha. then like we started texting all the time and he would send me cute smileys. but then he met this other girl. and he started talking to her more than me, and this boy wouldnt talk to me as much anymore. but now, he dropped this other girl because he found even another girl. i asked him if he liked her, and he always says no. but he knows i have a crush on him so i think sometimes he just says that to be nice. and like when i see this boy everyday in the gym he doesnt usually smile at me anymore, and i miss it alot. how can i get him back? please help! i answer your questions with the very BEST i possibly can!How can i get him to like me?
Id say you tried. You got close then...yeah. But you cant make him like you. There are other fish in the sea (: