Changed button to use initals.

src/docs/asciidoc/sdk/sample_code.adoc

@@ -31,7 +31,7 @@ This default project template creates a project called `JmeTests`. It contains a
 
 If you're using the current 3.1.0-Stable version of the SDK, you will need to set the `Source/Binary Format` from the `Project Properties` window to Java 1.7 or later. 
 
-*  To change the source, `btn:[R Mouse Btn]` select the jmeTestProject and then select `menu:Properties[Sources>Source/Binary Format]`, or from the File menu, with the jmeTestProject selected, `menu:File[Project Properties>Sources>Source/Binary Format]`.
+*  To change the source, `btn:[RMB]` select the jmeTestProject and then select `menu:Properties[Sources>Source/Binary Format]`, or from the File menu, with the jmeTestProject selected, `menu:File[Project Properties>Sources>Source/Binary Format]`.
 
 You will also need to remove the `jme3-jbullet` library and add `jme3-bullet` and `jme3-bullet-native` libraries. 
 
@@ -39,7 +39,7 @@ You will also need to remove the `jme3-jbullet` library and add `jme3-bullet` an
 
 [IMPORTANT]
 ====
-Press kbd:[Shift] + kbd:[F6] to run a class that is open in the editor, or `btn:[R Mouse Btn]` a class in the Project window and choose `btn:[Run File]`. You can run the `TestChooser` app by `btn:[R Mouse Btn]` selecting the project and pressing `btn:[Run]`. The TestChooser app allows you to easily navigate through all the test cases.
+Press kbd:[Shift] + kbd:[F6] to run a class that is open in the editor, or `btn:[RMB]` a class in the Project window and choose `btn:[Run File]`. You can run the `TestChooser` app by `btn:[RMB]` selecting the project and pressing `btn:[Run]`. The TestChooser app allows you to easily navigate through all the test cases.
 ====