function show(id) {

  var controls = $('.controls');
  var elements = $('.productList');
  var i = 0;
  
  while (i < elements.length) { elements[i].style.display = "none"; i++;  }
  
  //show this element
  var thatElement = document.getElementById(id);
  thatElement.style.display = 'block';
  //get id of control element
  var thisString = id;
  var thisElm = thisString.split('_');
  var j = 0;
  
  while (j < controls.length) { controls[j].setAttribute('class', 'controls'); j++; }

  document.getElementById(thisElm[0]).setAttribute('class', 'controls active');
}