How can I gain weight before Summer? PLEASE HELP!?

basically you just need to exercise. you will lose fat and gain muscle. you seem already very thin, so im guessing your tummy is the last place the weight needs to come off. keep exercising and it will, and then you will gain muscle. i recommend running, it will tone your ox and thighs. run up and down stairs too! and if you want muscle eat protein. its sounds more than anything you just want to be toned.