Canvas clicking stuff

[Tuvas]

I have a picture that is being displayed on a canvas interface, that I
want to do the following. When a mouse button is clicked on the canvas,
I want to pass to a function the X and Y coordinates of where this
mouse button was pushed. Futhermore, and I don't know if this is
possible, I would like to have a function that passes the same data
without a mouse button being clicked, or perhaps differentiating
between left and right clicks. Thanks for the help!