At the top of the element window you will find the element toolbar (also referred to as the navigation toolbar):

Here is the meaning of individual buttons:

• Contents - open the contents window with the tree structure of knowledge stored in your current collection
• Search - search for texts in your collection 
• Back (<) - move back to the most recently visited element (same as Alt+Left)
• Ahead (>) - revisit elements that have been viewed before with the button Back (<) (same as Alt+Right)
• History - view the list of recently visited elements
• Next - go to the next element (interpretation of this button depends on setting Next button options available from the Next button pull-down menu available on the professional level)
• Home - go to the root of the whole collection (i.e. the element that is the parent of the whole knowledge tree)
• Previous element - go to the previous element in the contents window
• Parent - go to the parent of the currently displayed element
• Next element - go to the next element in the contents window
• End - go to the last element in the knowledge tree in the contents window
• Reference link (not active in independent elements) - go to the source element from which a given element has been extracted in the process of incremental reading. By clicking the Reference link button, you can go to the article from which a given extract was taken
• Instant translation - turn on/off translating texts when the mouse moves over the element window
• Instant transcription - turn on/off providing phonetic transcription of texts when the mouse moves over the element window
• Synchronize - turn on/off selecting the currently displayed element in the contents window. Set this button in the down-state if you want to always be able to see the position of the displayed element in the contents window
• Bug report - (only in the debugging version) send a bug report via e-mail

Professional level

Note that the element toolbar may not be visible if Tools : Options : Data access : Hide navigation toolbar is checked