World's Easiest fudge recipe

My Girl Scouts did this recipe at our last meeting:  It's a breeze.

• 1 1/2 cups milk chocolate chips
  
• 1 1/2 cups semi-sweet chocolate chips
  
• 1 can sweetened condensed milk
  
• 1 1/2 teaspoons vanilla extract
  
• dash salt
  

Line 8" by 8" pan with foil.  Melt all ingredients together over low heat. Spread in pan.  Chill 2 hours until firm.