Combine pretzel crumbs, sugar and margarine; press on bottom and up side to rim of buttered 9-inch pie plate. Chill. In large bowl, combine sweetened condensed milk, Real Lime Brand Lime Juice and triple sec; mix well. Fold in whipped cream Pour into prepared crust. Freeze or chill until firm - 4 hours in freezer or 2 hours in refrigerator. Refrigerate or freez leftovers.