Update 4 1 horizontal scalar field

4-1-horizontal-scalar-field.md

@@ -12,7 +12,7 @@ Open your data file(s), using buttons on the _Home_ menu category of _Menu Bar_.
 
 In order to visualize the distribution of the variable on a layer, you can either
 
-* click the _Add Horizontal Plane_ menu button on _Layer_ menu category, and select variable/area/level, and then click "OK", or 
+* click the _Add Horizontal Plane_ menu button on _Layer_ menu category, select variable/area/level, and then click "OK", or 
 * right-click the temperature variable on the _Variables Pane_, select _Add Horizontal Plane'.
 * double-click the temperature variable on the _Variables Pane_, and click 'OK' to add layer.