Circle Buttons in CSS

this is just a small trick in css to create circle like buttons.
to achieve this just put the width and height equal to each other and equal to the css border radius of a button.
if the button is 20 by 20 px than to make it look like a circle in javafx css:

.circlebutton
{
    -fx-border-radius: 20;
}

i believe this also applies to web css3 but i haven’t tested it.
the following picture illustrates a zoom panel that i’ve done. the two buttons for zoom in and zoom out look circle like.