Will i lose weight if i keep doin this.?

o.k..im 5"6 an weigh 135 pounds..i would rely like to lose about 10-15 pounds in a month...so im starting a diet tomarrow...for breakfast a piece of fruit like a peach..for lunch a small salad or some toast...an a small dinner....i also do 500 sit-ups a day,an walk for about an hour or two a day with some jogging also...will this help me lose my 10-15 pounds in a month...an im going to drink plenty of water an no junkfood/fatty food or NO soda/diet soda either....how long will this take me..?