Preheat oven to 350 degrees. Mix crushed pretzels sugar and butter. Press into a 9x13 pan. Bake for 10 min. Beat the sugar and cream cheese. Fold in cool whip. Spread over cooled crust. Refridgerate 20 min. Stir together jello and boiling water. Mix in strawberries. Pour over cream cheese mixture. Refridgerate 1 hour.