var addEvent;
if (document.addEventListener) {
  addEvent = function(element, type, handler) {
    element.addEventListener(type, handler, false);
  };
} else if (document.attachEvent) {
  addEvent = function(element, type, handler) {
    element.attachEvent("on" + type, handler);
  };
} else {
  addEvent = new Function; // not supported
}

var toggleSpares = function () {
    return {
        "group" : {},
        "trigger" : {},
        "init" : function () {
            toggleSpares.group = document.getElementById("spares_group");
            if (toggleSpares.group === false)
            toggleSpares.group.style.display = "none";
            
            toggleSpares.trigger = document.getElementById("nature_of_enquiry");
            toggleSpares.toggle(toggleSpares.group, toggleSpares.trigger, "Spares");
            
            addEvent(toggleSpares.trigger, 'change', function(){
                toggleSpares.toggle(toggleSpares.group, toggleSpares.trigger, "Spares");
            });
        },
        "toggle" : function (ele, triggerEle, triggerValue) {
            if (triggerEle.value === triggerValue) {
                ele.style.display = 'block';
            } else {
                ele.style.display = 'none';
            }
        }
    };
}();

addEvent(window, 'load', toggleSpares.init);