if (document.images) {
      
      home_off = new Image();
      home_off.src = "buttons/home1.gif"       
      preconf_off = new Image();
      preconf_off.src = "buttons/preconfwkshp1.gif"
      program_off = new Image();
      program_off.src = "buttons/program1.gif"
      registration_off = new Image();
      registration_off.src = "buttons/registration1.gif"
      events_off = new Image();
      events_off.src = "buttons/events1.gif"
      studentshowcase_off = new Image();
      studentshowcase_off.src = "buttons/studentshowcase1.gif"
      exhibitorlist_off = new Image();
      exhibitorlist_off.src = "buttons/exhibitorlist1.gif"
	  directions_off = new Image();
      directions_off.src = "buttons/directions1.gif"
      contacts_off = new Image();
      contacts_off.src = "buttons/contacts1.gif"
	  exhibitor_off = new Image();
	  exhibitor_off.src = "buttons/exhibitor1.gif"
      sponsor_off = new Image();
      sponsor_off.src = "buttons/sponsorpartner1.gif"

       
      home_on = new Image();
      home_on.src = "buttons/home2.gif"
      preconf_on = new Image(); 
      preconf_on.src = "buttons/preconfwkshp2.gif"
      program_on = new Image(); 
      program_on.src = "buttons/program2.gif"
      registration_on = new Image();
      registration_on.src = "buttons/registration2.gif"
      events_on = new Image();
      events_on.src = "buttons/events2.gif"
      studentshowcase_on = new Image();
      studentshowcase_on.src = "buttons/studentshowcase2.gif"
	  exhibitorlist_on = new Image();
      exhibitorlist_on.src = "buttons/exhibitorlist2.gif"
      directions_on = new Image();
      directions_on.src = "buttons/directions2.gif"
      contacts_on = new Image();
      contacts_on.src = "buttons/contacts2.gif"
	  exhibitor_on = new Image();
	  exhibitor_on.src = "buttons/exhibitor2.gif"
      sponsor_on = new Image();
      sponsor_on.src = "buttons/sponsorpartner2.gif"


                 
}

function buttonOff(imgName) {
   document[imgName].src = eval(imgName + "_off.src");
}

function buttonOn(imgName) {
   document[imgName].src = eval(imgName + "_on.src");
}