home_on = new Image ( );
	home_off = new Image ( );
	home_on.src = "images/leftnav/home_button_roll.png";
	home_off.src = "images/leftnav/home_button.png";
	
	whatis_on = new Image ( );
	whatis_off = new Image ( );			
	whatis_on.src = "images/leftnav/whatisMPM_button_roll.png";
	whatis_off.src = "images/leftnav/whatisMPM_button.png";

	sheep_on = new Image ( );
	sheep_off = new Image ( );			
	sheep_on.src = "images/leftnav/MPMsheep_button_roll.png";
	sheep_off.src = "images/leftnav/MPMsheep_button.png";
	
	network_on = new Image ( );
	network_off = new Image ( );			
	network_on.src = "images/leftnav/MPMnetwork_button_roll.png";
	network_off.src = "images/leftnav/MPMnetwork_button.png";	
	
	industry_on = new Image ( );
	industry_off = new Image ( );			
	industry_on.src = "images/leftnav/sheep_industry_button_roll.png";
	industry_off.src = "images/leftnav/sheep_industry_button.png";
	
	services_on = new Image ( );
	services_off = new Image ( );			
	services_on.src = "images/leftnav/MPMservices_button_roll.png";
	services_off.src = "images/leftnav/MPMservices_button.png";
	
	benchmarking_on = new Image ( );
	benchmarking_off = new Image ( );			
	benchmarking_on.src = "images/leftnav/benchmarking_button_roll.png";
	benchmarking_off.src = "images/leftnav/benchmarking_button.png";
	
	studs_on = new Image ( );
	studs_off = new Image ( );			
	studs_on.src = "images/leftnav/studs_button_roll.png";
	studs_off.src = "images/leftnav/studs_button.png";
	
	links_on = new Image ( );
	links_off = new Image ( );			
	links_on.src = "images/leftnav/links_button_roll.png";
	links_off.src = "images/leftnav/links_button.png";
	
	contact_on = new Image ( );
	contact_off = new Image ( );			
	contact_on.src = "images/leftnav/contactus_button_roll.png";
	contact_off.src = "images/leftnav/contactus_button.png";
	
	feedback_on = new Image ( );
	feedback_off = new Image ( );			
	feedback_on.src = "images/leftnav/enquiry_button_roll.png";
	feedback_off.src = "images/leftnav/enquiry_button.png";		
	
	function button_on ( imgName )
	{
		if ( document.images )
	  	{
	    		butOn = eval ( imgName + "_on.src" );
	    		document[imgName].src = butOn;
	  	}
	}

	function button_off ( imgName )
	{
	  	if ( document.images )
	  	{
	  	  	butOff = eval ( imgName + "_off.src" );
	  	  	document[imgName].src = butOff;
	  	}
	}