Directly no, PHP is server side but the buttons are client side.
The best you can do is have the button to refresh the page while passing a trigger to your functions.
For example if you setup the button as a link to your page such as
page.php?button1=yes
then you could check this on your page
if(isset($_GET['button1']))
{
button1_function();
}
You could also make the button linked to a form and pass lots of variables via the POST method ($POST rather than $GET)
