There is no built-in oncontextmenu event handler in jQuery, but you can do something like this:
$(document).ready(function(){ 
  document.oncontextmenu = function() {return false;};
  $(document).mousedown(function(e){ 
    if( e.button == 2 ) { 
      alert('Right mouse button!'); 
      return false; 
    } 
    return true; 
  }); 
});
Basically I cancel the oncontextmenu event of the DOM element to disable the browser context menu, and then I capture the mousedown event with jQuery, and there you can know in the event argument which button has been pressed.
You can try the above example here.