append /remove anchor name from current url without refresh

I want that on click event to append/remove the anchor name "#on" to be added to the current url without reloading the page, or use the href='#on' from links because it makes my page jump

Eg: http://www.example.com/page.html#on so I can get the detect the users that come from that url and call the On() function

function On()
{   
   //append to current url the anchor "#on"                 
}

function Off()
{   
  //remove from the current url the anchor "#on"                    
}

$('.on').live('click', function() {
  On();
  return false;    
}); 


$('.off').live('click', function() {
  Off();
  return false;    
});