(Chapter 3) Implemented "About" button successfuly

• Today, I implemented actual activity for ABOUT button. When I press the button, it navigates to the next  window in the format so called "Dialog box" since I defined the theme of "Dialog" in AndroidMainifest.xml. 

• AndroidMainifest.xml is the file which maps the activities to the xml pages or texts you have created.

• XML (layout) and Java activities are synced with IDs. If there are some discrepancies in between, Eclipse will put bug marks in the files and also on the lines which have problems so that the developer will know easily and fix them.  

• For this feature, I needed to call OnClickLisner function. Unlike C, Java calls its functions "Methods". Methods belong to a certain Class. 

• Other buttons can be implemented exactly the same way.