In a medium bowl, combine crushed pretzels, melted margarine, and 1/4 cup sugar. Press mixture into a 9x13 inch baking pan.
Bake for 8 to 10 minutes. Let cool.
In a large mixing bowl, beat cream cheese, frozen whipped topping, and 1 cup sugar. Pour over pretzel crust.
In a large saucepan, combine boiling water and strawberry-flavored gelatin; bring to a boil. Stir in frozen strawberries. When it begins to thicken, pour over cream cheese filling. Serve.