Melt chocolate with 2 tablespoons of milk over low heat or in the microwave, stirring until chocolate is melted and smooth. Beat sugar into cream cheese. Add remaining milk and chocolate mixture. Beat until smooth. Fold in cool whip. Spoon into crust, and chill until firm, usually overnight. Store leftover pie in refrigerator. Notes: This can be frozen, and is good to have on hand. This is a good, easy, light, summer-time dessert.