Pink Lemonade Pie

This is so good and easy. I used to have Eric mix it up for me when he was a teenager. Very good on a hot summer's day.
PINK LEMONADE PIE
1 graham cracker pie crust (large one)
1 sm. can (6 oz.) frozen pink lemonade, thawed (can use limeade)
1 sm. container cool whip
1 can condensed milk
Mix together thawed pink lemonade, cool whip, and condensed milk. Beat until smooth and pour into pie shell. Freeze until firm. Garnish with lemon slices.