$(document).ready(function() {
 
 
 
$('img.nav_img').hover(function()
 {
  //turn 'em all off
  $('.navigation').find("img").each(function(){
  	this.src = this.src.replace("_selected_off","_unselected_off");
  });
  this.src = this.src.replace("_off","_on");
 },
 function()
 {
  this.src = this.src.replace("_on","_off");
   //turn 'em all off
  $('.navigation').find("img").each(function(){
  	this.src = this.src.replace("_unselected_off","_selected_off");
  });
 });

});