Chicken Poppyseed Casserole

(This one is actually from my Sister-in-law Lisa)

4 cups cooked and diced chicken
2 cans cream of chicken soup (undiluted)
3 cups sour cream
2 sleeves Ritz crackers, crushed
2 sticks real butter, melted
(it is probably better with real butter but I use margarine because that is what I have)
2 Tablespoons poppy seeds

Preheat oven to 350 degrees. Grease a 9x13 inch casserole dish. In a large bowl, combine chicken, soup, and sour cream. Mix well until blended. In a separate bowl, combine crushed crackers, melted butter, and poppy seeds. Mix one half of the cracker mixture with the chicken mixture and spread in casserole dish. Top with remaining cracker mixture. Bake uncovered for 30 minutes at 350 degrees.