I am trying to do some java script coding for search button and if user do not enter any data and it should give error but its not working

        if(requests.length == 0)
        {
            h4.innerHTML = "No service requests found";
            container.appendChild(h4); 
        }
        else 
        {
            h4.innerHTML = "Showing " + requests.length + " 311 Service Requests in Winnipeg 
            that contains " + neighbourhood.toUpperCase();
            container.appendChild(h4); 
            add_requests(requests); 
         }
         })