Help! i need to lose 15 kgs. and urgently i need to lose 5 kgs in a month for a competition.?

Go swimming, and watch what you eat. You need cardio, and since your knee is not in the greatest condition I would say go swimming in a near by pool or lake, do loads of crunches, and sit-ups... and do a few leg lifts... Find a bun and thigh work out vid and use that to tone your lower body... As far as eating watch what you eat and don't diet... Eat loads of salads and cut out everything fatty, meaty, and especially salty and sweet... Proportion your meals... It's a hard journey but it'll pay off... And last but not least don't give up... Motivation is key... if you don't have motivation, it's going to be a bumpy ride.