Mix cranberry juice cocktail, grape juice and pectin in 3 litre saucepan until smooth. Heat to boiling over high heat, stirring constantly. Stir in sugar, all at once. Heat to boiling, stirring constantly. Boil and stir 1 minute; remove from heat. Quickly skim off foam. Immediately pour into hot sterilized jars. Let jars stand1 hour. Cover with lids. Refrigerate no longer than 3 weeks, or freeze no longer than 6 months. Thaw before serving. ABOUT 5 HALF-PINTS JELLY; 35 CALORIES PER TABLESPOON