How can I lose weight over spring break ?

Today March 14 , 2011 spring break starts , I am ready to excercise and get on my way to a healthy good looking body . I am 13 measure 5'3 1/2 and weigh 123 lbs . I think that seems very reasonable according to my measurements and age , but those 123 lbs . dont look good on me , they are actually on my tummy area and so it bothers me that I look fat , specially now that summer is coming . I want to lose weight so I can look good in a bathing suite ,without shorts . -.- what am trying to do is lose some tummy , so I can have a flat stomach and nice legs that are firm like so - - > a href="http://www.google.com/imgres?imgurl=http://i61.photobucket.com/albums/h60/claudia565/Image2-4.png&imgrefurl=http://foro.univision.com/t5/Nuestra-Belleza-Latina/ANA-PATRICIA-por-su-camino-en-el-NBL-2010/td-p/395468693/page/3&usg=__wqr9nrs-9PNUxV0GX_jDSoZl5i8=&h=319&w=443&sz=225&hl=en&start=145&zoom=1&tbnid=c7lMUHIpqQnlyM:&tbnh=154&tbnw=208&ei=2Gp-TcnkJ4OgsQPQ9umDBg&prev=/images%3Fq%3Dana%2Bpatricia%2Bgonzalez%26um%3D1%26hl%3Den%26biw%3D1280%26bih%3D657%26tbs%3Disch:10%2C3690&um=1&itbs=1&iact=hc&vpx=260&vpy=297&dur=203&hovh=190&hovw=265&tx=68&ty=103&oei=kWp-TeyGNoassAPrmuXqBQ&page=8&ndsp=21&ved=1t:429,r:8,s:145&biw=1280&bih=657" rel="nofollow"http://www.google.com/imgres?imgurl=http…/a