This brings you to the dialog box to do an advanced search for an object. You can search for planets, stars, deep sky objects, comets or asteroids. Click here to read more about the Advanced Search dialog box.
If you want to edit labels, the Edit Label mode needs to be set to editable, and that's just what a click on this line is all about. Every click on this line inverts the Edit Label mode, So, in fact it doesn't change the content of any label. You also can change the Edit Label mode by a click on the icon on the objects bar.
To read how to modify a label, read about the modification of labels.
Copies the currently active chart into the system clipboard, so you can easily past it as an image in a word processor or imaging program.
This will undo the last action executed in the program.
This will redo the last action that was previously cancelled by an Undo action.