// Status=review
The following buttons appear just under the decoded text windows on
the main screen:

//.Main UI Controls
image::main-ui-controls.png[align="left",width=650,alt="Main UI Controls"]

* *Log QSO* raises a dialog window pre-filled with known information
about a QSO you have nearly completed.  You can edit or add to this
information before clicking *OK* to log the QSO.  If you check *Prompt
me to log QSO* on the *Setup* menu, the program will raise the
confirmation screen automatically when you send a message containing
73.

//.Log QSO Window
image::log-qso.png[align="center",alt="Log QSO"]

* *Stop* will terminate normal data acquisition in case you want to
freeze the waterfall or open and explore a previously recorded audio
file.

* *Monitor* toggles normal receive operation on or off.  This button
is highlighted in green when the _WSJT-X_ is receiving.  If you are
using CAT control, toggling *Monitor* OFF relinquishes control of the
rig; if *Monitor returns to last used frequency* is selected on the
*Settings | General* tab, toggling *Monitor* back ON will return to
the original frequency.

* *Erase* clears the right-hand decoded text window. 
Double-clicking *Erase* clears both text windows.

* *Clear Avg* is present only in modes that support message averaging.
It provides a way to erase the accumulating information, thus
preparing to start a new average.

* *Decode* tells the program to repeat the decoding procedure at the
Rx frequency (green marker on waterfall scale), using the most recently
completed sequence of received data.  

* *Enable Tx* toggles automatic T/R sequencing mode on or off and
highlights the button in red when ON.  A transmission will start at
the beginning of the selected (odd or even) sequence, or immediately
if appropriate.  Toggling the button to OFF during a transmission
allows the current transmission to finish.

* *Halt Tx* terminates a transmission immediately and disables
automatic T/R sequencing.

* *Tune* toggles the program into Tx mode and generates an unmodulated
carrier at the specified Tx frequency (red marker on waterfall scale).
This process is useful for adjusting an antenna tuner or tuning an
amplifier.  The button is highlighted in red while *Tune* is active.
Toggle the button a second time or click *Halt Tx* to terminate the
*Tune* process.  Note that activating *Tune* interrupts a receive
sequence and will prevent decoding during that sequence.