checkRecipe: function (recipe) {
                var i, j, item,
                        usedGids = [],
                        matchList = [];

                for (i = 0; i < recipe.Ingredients.length; i += 1) {
                        var optimalItem;
                        for (j = 0; j < this.validIngredients.length; j += 1) {
                                if (usedGids.indexOf(this.validIngredients[j].gid) === -1 &&
                                                (this.validIngredients[j].classid === recipe.Ingredients[i] || (recipe.Ingredients[i] === "pgem" &&
                                                this.gemList.indexOf(this.validIngredients[j].classid) > -1))
                                                ) {
                                        item = me.getItem(this.validIngredients[j].classid, -1, this.validIngredients[j].gid);

                                        if (item && this.validItem(item, recipe)) { // 26.11.2012. check if the item actually belongs to the given recipe
                                                if(item.location === 3 || !optimalItem) {
                                                        optimalItem = item;
                                                }
                                                break;
                                        }
                                }
                        }
                        if(!optimalItem) {
                                // don't repeat the same item
                                usedGids.push(optimalItem.gid);
                                // push the item into the match list
                                matchList.push(copyUnit(optimalItem));
                        }

                        // no new items in the match list = not enough ingredients
                        if (matchList.length !== i + 1) {
                                return false;
                        }
                }

                // return the match list. these items go to cube
                return matchList;
        },