improve docs

docs/mithril.request.md

@@ -487,7 +487,7 @@ where:
 		var demo = {}
 
 		demo.controller = function() {
-			var users = m.request({method: "GET", url: "test.json", background: true, initialValue: []})
+			var users = m.request({method: "GET", url: "/api/users", background: true, initialValue: []})
 			users.then(m.redraw)
 			return {users: users}
 		}
@@ -503,7 +503,41 @@ where:
 		```
 		
 		It's strongly recommended that you set an `initialValue` option in ALL requests if you set the `background` option to true.
+		
+		When calling multiple background AJAX requests, it's recommended that you use [`m.sync`](mithril.sync.md) to batch redraw once at the end of all requests, as opposed to repeatedly redrawing after every request:
 
+		```javascript
+		var demo = {}
+
+		demo.controller = function() {
+			var users = m.request({method: "GET", url: "/api/users", background: true, initialValue: []})
+			var projects = m.request({method: "GET", url: "/api/projects", background: true, initialValue: []})
+			
+			m.sync([users, projects]).then(m.redraw)
+			
+			return {users: users, projects: projects}
+		}
+		```
+		
+		Make sure to add null checks if your request value can be null
+		
+		```javascript
+		var demo = {}
+
+		demo.controller = function() {
+			var user = m.request({method: "GET", url: "/api/users/1", background: true, initialValue: null})
+			user.then(m.redraw)
+			return {user: user}
+		}
+
+		demo.view = function(ctrl) {
+			return m("div", [
+				//in the first redraw, there's no user, so ensure we don't throw an error
+				ctrl.user ? ctrl.user.name : "no user"
+			])
+		}
+		```
+		
 	-	**any initialValue** (optional)
 	
 		The value that populates the returned getter-setter before the request completes. This is useful when using the `background` option, in order to avoid the need for null checks in views that may be attempting to access the returned getter-setter before the asynchronous request resolves.