My Grandmother had 8 children and there was a housefull when we all got together, which was frequently since we all lived in the same city. She made this quite a bit.
Boil together:
1 c. sugar
4 1/2 c. water
Add:
1 (6 oz.) can frozen orange juice
1 (6 oz.) can frozen lemon juice
1 pt. vodka mix
Freeze. When frozen, stir to serve. Add 1/2 slush plus 1/2 Squirt, 7-Up or soda.