Hi @lubos,
I use the back (previous) button on my mouse a lot (as a lot of others i assume) in several programs. So it would improve workflow a lot if the back button in Manager could be “clicked” with that (extra) button on my mouse. I think it’s a small but very workflow improving function. By the way, is there a keyboard shortcut for the back button?
What back / previous button are you referring to? I’m familiar with most mice having a Left/Right click, and a scroll wheel or trackpad, but a back button sounds unusual. Is it a gaming mouse?
That kind of customisation is likely not going to be something that Manager can easily do. The best solution would be to find a keyboard key that performs the same task, then use software from your mouse manufacturer to map your ‘back’ button to that key press.
I think Backspace (or delete on Mac) on your keyboard will do what you want.
a five-button mouse is now very commonly available. most users configure the additional buttons for backward and forward function. atleast i used to do that when using a desktop 
this would not be possible unless Manager is built with support for mouse drivers. most of the applications will not support the functions of additional mouse buttons. as far as i can remember the buttons would only work in file browsers after properly configuring the same in your mouse properties.
The back button on the top left of Manager.
The Backspace button does it partially but not for instance when you edit sales invoices. I use a Logitech M570 trackball and i have just tried to ‘connect’ the back-button to Manager and it didn’t work.
I think, because most mice are normalized, it is not very difficult for @lubos to implement this and i think you will agree that it would be a nice improvement.
Again, you would likely need to use software from your mouse manufacturer to map your ‘back’ button (on the mouse) to a key press (e.g. Backspace).
This is the download page from Logitech for your device: Logitech Support + Download
Note: Never download drivers from any website other than the official manufacturer.
You want the ‘Logitech Control Center’:
That is because when you are editing a form, the backspace or delete key must be available as an editing input.
Also remember that Manager must work across multiple operating systems.
The reason backspace button has been disabled on forms is that people have been accidentally navigating back to previous page when they intended to remove text from a text field.
Google Chrome went as far as removing backspace shortcut altogether, see: Google Chrome to stop backspace being a ‘back’ button, saving people from accidentally deleting everything | The Independent | The Independent
You can test it. Pressing backspace in Google Chrome will give you a notice to use Alt + Left Arrow instead.