Uniting Paths
You can combine two or more paths into one.
- Click Selection Tool 
 on the  Tool Palette.
 - While holding down the <Shift> key, click on each path object to be combined.
 - Select the [Modify > Combine Path > Union] menu command, or click the triangle on the Combine Path button on the Object Toolbar and select Union.
 - If any of the original paths did not overlap with any other original path, a new path object named ‘Compound Path’ will appear in the  Layers window. Otherwise, the bottom-most original path will be changed to the union of the original paths.