code: function searchInput() {
  			var i, item,
  				searchText = moduleSearch.value.toLowerCase(),
  				listItems = dropDownList.children;
  
  			for ( i = 0; i < listItems.length; i++ ) {
  				item = listItems[ i ];
  				if ( !searchText || item.textContent.toLowerCase().indexOf( searchText ) > -1 ) {
  					item.style.display = "";
  				} else {
  					item.style.display = "none";
  				}
  			}
  		}
docs: Processes module search box input