var test='1';
function downBtn()
 {
MM_preloadImages('../images/nav_home1.gif','../images/nav_products1.gif','../images/nav_sample1.gif','../images/nav_news1.gif','../images/nav_about1.gif','../images/nav_contact1.gif')
  if (self.location.href.indexOf('/products/')!=-1)
     document.getElementById('products').src='../images/nav_products2.gif';
  else if (self.location.href.indexOf('/sample_request/')!=-1)
     document.getElementById('sample').src='../images/nav_sample2.gif';
  else if (self.location.href.indexOf('/news_events/')!=-1)
     document.getElementById('news').src='../images/nav_news2.gif';
  else if (self.location.href.indexOf('/about_us/')!=-1)
     document.getElementById('about').src='../images/nav_about2.gif';
  else if (self.location.href.indexOf('/contact_us/')!=-1)
     document.getElementById('contact').src='../images/nav_contact2.gif';
  else
     alert('could not match the URL');
    }