var compare_ids = new Array();

function add_to_compare(id) {
  for (var idx = 0; idx < compare_ids.length; idx++) {
    if (compare_ids[idx] == id) {
      compare_ids.splice(idx, 1);
      return;
    }
  }
  
  compare_ids.push(id);
  compare_ids.sort();
}

function compare() {
  if (compare_ids.length < 2) {
    alert('Trebuie sa selectati minim doua produse pentru a putea efectua o comparatie!');
    return;
  }
  
  var day = new Date();
  var id = day.getTime();
  var url = '/compare.php?ids=' + compare_ids.join(',') ;
  eval("page" + id + " = window.open(url, '" + id + "', 'toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=1,width=800,height=600');"); 
}