How to emulate keypress on mouse click?

I've spent days searching without luck.
I need help with the following:

I have a program that have some hotkeys set to trigger some events. I would like to activate those hotkeys from inside firefox by clicking on a button. I'm not looking for keypress events, it has to be a button click.
So, let's say I click on the button that executes a javascript code that emulates F7 or CTRL+A or whatever key or key combination. Can you guys please help with to find a solution?
Oh, and I need it to work with Firefox only.

Thanks!

I've spent days searching without luck.
I need help with the following:

I have a program that have some hotkeys set to trigger some events. I would like to activate those hotkeys from inside firefox by clicking on a button. I'm not looking for keypress events, it has to be a button click.
So, let's say I click on the button that executes a javascript code that emulates F7 or CTRL+A or whatever key or key combination. Can you guys please help with to find a solution?
Oh, and I need it to work with Firefox only.

Thanks!

Not possible. You cannot emulate a key press. Javascript cannot access the operating system or the Windows registry, nor alter the default behaviour of the browser.


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Thank you for the answer!