if (document.images) {
    homebuttonup       = new Image();
    homebuttonup.src   = "./images/nav_home.gif" ;
    homebuttondown     = new Image() ;
    homebuttondown.src = "./images/nav_home_on.gif" ;

 	companybuttonup       = new Image();
    companybuttonup.src   = "./images/nav_company.gif" ;
    companybuttondown     = new Image() ;
    companybuttondown.src = "./images/nav_company_on.gif" ;

  	servicesbuttonup       = new Image();
    servicesbuttonup.src   = "./images/nav_services.gif" ;
    servicesbuttondown     = new Image() ;
    servicesbuttondown.src = "./images/nav_services_on.gif" ;

  	careersbuttonup       = new Image();
    careersbuttonup.src   = "./images/nav_careers.gif" ;
    careersbuttondown     = new Image() ;
    careersbuttondown.src = "./images/nav_careers_on.gif" ;

  	clientsbuttonup       = new Image();
    clientsbuttonup.src   = "./images/nav_clients.gif" ;
    clientsbuttondown     = new Image() ;
    clientsbuttondown.src = "./images/nav_clients_on.gif" ;

 	perspectivesbuttonup       = new Image();
    perspectivesbuttonup.src   = "./images/nav_perspectives.gif" 
    perspectivesbuttondown     = new Image() ;
    perspectivesbuttondown.src = "./images/nav_perspectives_on.gif" ;

  	contactbuttonup       = new Image();
    contactbuttonup.src   = "./images/nav_contact.gif" ;
    contactbuttondown     = new Image() ;
    contactbuttondown.src = "./images/nav_contact_on.gif" ;

	companyoverviewbuttonup       = new Image();
    companyoverviewbuttonup.src   = "./images/nav_sub_company.gif" ;
    companyoverviewbuttondown     = new Image() ;
    companyoverviewbuttondown.src = "./images/nav_sub_company_on.gif" ;

  	historybuttonup       = new Image();
    historybuttonup.src   = "./images/nav_sub_history.gif" ;
    historybuttondown     = new Image() ;
    historybuttondown.src = "./images/nav_sub_history_on.gif" ;

  	people_and_valuesbuttonup       = new Image();
    people_and_valuesbuttonup.src   = "./images/nav_sub_people_history.gif" ;
    people_and_valuesbuttondown     = new Image() ;
    people_and_valuesbuttondown.src = "./images/nav_sub_people_history_on.gif" ;

  	servicessubbuttonup       = new Image();
    servicessubbuttonup.src   = "./images/nav_sub_services.gif" ;
    servicessubbuttondown     = new Image() ;
    servicessubbuttondown.src = "./images/nav_sub_services_on.gif" ;

  	approachbuttonup       = new Image();
    approachbuttonup.src   = "./images/nav_sub_approach.gif" ;
    approachbuttondown     = new Image() ;
    approachbuttondown.src = "./images/nav_sub_approach_on.gif" ;
   
    industriesbuttonup       = new Image();
    industriesbuttonup.src   = "./images/nav_sub_industries.gif" ;
    industriesbuttondown     = new Image() ;
    industriesbuttondown.src = "./images/nav_sub_industries_on.gif" ; 

  	careersoverviewbuttonup       = new Image();
    careersoverviewbuttonup.src   = "./images/nav_sub_careers.gif" ;
    careersoverviewbuttondown     = new Image() ;
    careersoverviewbuttondown.src = "./images/nav_sub_careers_on.gif" ;

  	skills_and_traitsbuttonup       = new Image();
    skills_and_traitsbuttonup.src   = "./images/nav_sub_skills_traits.gif" ;
    skills_and_traitsbuttondown     = new Image() ;
    skills_and_traitsbuttondown.src = "./images/nav_sub_skills_traits_on.gif" ;

  	working_at_xby2buttonup       = new Image();
    working_at_xby2buttonup.src   = "./images/nav_sub_working_at_xby2.gif" ;
    working_at_xby2buttondown     = new Image() ;
    working_at_xby2buttondown.src = "./images/nav_sub_working_at_xby2_on.gif" ;

	positionsbuttonup             = new Image();
	positionsbuttonup.src         = "./images/nav_sub_positions.gif" ;
	positionsbuttondown           = new Image();
	positionsbuttondown.src       = "./images/nav_sub_positions_on.gif" ;

	clientssubbuttonup       	  = new Image();
    clientssubbuttonup.src  	  = "./images/nav_sub_clients.gif" ;
    clientssubbuttondown     	  = new Image() ;
    clientssubbuttondown.src 	  = "./images/nav_sub_clients_on.gif" ;

  	clients_servicesbuttonup       = new Image();
    clients_servicesbuttonup.src   = "./images/nav_sub_clients_service.gif" ;
    clients_servicesbuttondown     = new Image() ;
    clients_servicesbuttondown.src = "./images/nav_sub_clients_service_on.gif" ;

	clients_industrybuttonup        = new Image();
	clients_industrybuttonup.src    = "./images/nav_sub_clients_practice.gif" ;
	clients_industrybuttondown      = new Image();
	clients_industrybuttondown.src  = "./images/nav_sub_clients_practice_on.gif" ;
}

var previousDivDisplay = "";
var previousButton = "";

function buttondown( buttonname )
{
    if (document.images) {
      document[ buttonname ].src = eval( buttonname + "down.src" );
    }

	if (previousButton != "")
	{
		buttonup(previousButton);
	}

    showSubDiv(buttonname);

}

function subbuttondown( buttonname )
{
    if (document.images) {
      document[ buttonname ].src = eval( buttonname + "down.src" );
    }
}

function buttonup ( buttonname )
{
    if (document.images) {
      document[ buttonname ].src = eval( buttonname + "up.src" );
    }
}

function showSubDiv(buttonname)
{
 	hideSubDiv();
 	divName = buttonname + "Div";
 	var divToShow = document.getElementById(divName);
    if (divToShow)
    {
   		divToShow.style.display = "block";
   		previousDivDisplay = divToShow;
   		subbuttondown(buttonname);
   		previousButton = buttonname;
    }
	else
	{
		hideSubDiv();
	}
}

function hideSubDiv()
{
    if (previousDivDisplay != "")
    {
    	previousDivDisplay.style.display = "none";
    	previousDivDisplay = "";
    }
}