添加td_tech_title非空判断

app/views/layouts/base_users.html.erb

@@ -82,7 +82,11 @@
                           break;
                   }
               }
-              document.getElementById('td_tech_title').innerHTML = title1;
+              var obj = document.getElementById('td_tech_title');
+              if(!(obj == "undefined" || obj == null))
+              {
+                  obj.innerHTML = title1;
+              }
           }
         </script>