Weight loss

I'm on a mission to loose weight. Since starting work at my hospital I gained 15 pounds. I've only worked there a year so I'm afraid I will be very overweight soon. So I've been using my elliptical trainer every day and really watching what I eat. It's hard when the food at work is all junk.
I also want to fit into my kimono better. They are just a tad tight now. My current weight loss goal is 15 pounds. I think I can get back to feeling thin in two months or so. We'll see.