SetTimeout function

I have a problem, I don't know why to make this line of code to work:
setTimeout("openingBox(" + box + ", " + current + ", " + max + ")", 20);
  The box, current, max variabiles exista and the openingBox too, I just can't make the setTimeout function to work with variables as parameters, could someone please help me do this?

try setTimeout(function(){...}, 20);