Update 3 3 open layer

3-3-open-layer.md

@@ -9,12 +9,18 @@ After opening data files, you can add layers to the 3D-image in the **Rendering
 
     ![](img/3-3-1-add-layer.png)
 
-1.  In *Edit [Layer Name] Layer* dialog box, such as *Edit Horizontal Plane Layer*, customize your layer and click *OK* button.
+1.  In *Edit [Layer Name] Layer* dialog box, such as *Edit Horizontal Plane Layer*, select the variable you want to show in *Select Variable* and set the vertical altitude and map area of the layer in *Area and level to Display*, and click *OK* button.
+
 
     ![](img/3-3-1-edit-layer.png)
 
 
-After adding a layer, the program adds one more category corresponding to the added layer in *Menu Category*, such as *Horizontal Plane* category. 
+ 
+After adding a layer, such as *Horizontal Plane*, **Rendering Pane** displays data of the selected variable on the layer, **Layers Pane** displays the added layer, and **Actions Pane** displays the *Add layer* action.
+
+![](img/3-3-1-add-layer-result.png)
+
+In addition, the program generates one more category corresponding to the added layer in *Menu Category*, such as *Horizontal Plane* category. 
 
 ![](img/3-3-1-add-category.png)
 
@@ -27,18 +33,17 @@ Note that the name of the added category and its ribbon are displayed differentl
 
 
 ##### Viewing data
-To display the data of a variable on the current layer, you can *select* that variable in the list (on the **Variables Pane**) and:
+To display data of another variable on the current layer, you can *select* that variable in the list (on the **Variables Pane**) and:
 
 *  double-click on that variable; or 
 *  click the first button on the control bar, then select *Show on Current Layer*; or
 *  right-click and select *Show on Current Layer*.
 
-Note that when you add a layer, data of a variable is displayed. You can change the 
-
 
+### 2. Layers Management
 
+After adding a layer, the 
 
-### 2. Layers Management
 
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