if (document.images) {
	b1_on = new Image();
	b1_on.src = "images/menu/research_on.gif";
	b1_off = new Image();
	b1_off.src = "images/menu/research_off.gif";
	b2_on = new Image();
	b2_on.src = "images/menu/services_on.gif";
	b2_off = new Image();
	b2_off.src = "images/menu/services_off.gif";	
	b3_on = new Image();
	b3_on.src = "images/menu/whoweare_on.gif";
	b3_off = new Image();
	b3_off.src = "images/menu/whoweare_off.gif";
	b4_on = new Image();
	b4_on.src = "images/menu/whatotherssay_on.gif";
	b4_off = new Image();
	b4_off.src = "images/menu/whatotherssay_off.gif";
	b5_on = new Image();
	b5_on.src = "images/menu/history_on.gif";
	b5_off = new Image();
	b5_off.src = "images/menu/history_off.gif";	
	b6_on = new Image();
	b6_on.src = "images/menu/hsi_on.gif";
	b6_off = new Image();
	b6_off.src = "images/menu/hsi_off.gif";	
	b7_on = new Image();
	b7_on.src = "images/menu/contactus_on.gif";
	b7_off = new Image();
	b7_off.src = "images/menu/contactus_off.gif";
	b8_on = new Image();
	b8_on.src = "images/menu/home_on.gif";
	b8_off = new Image();
	b8_off.src = "images/menu/home_off.gif";		
				} 
function dsgo(imgName) { 
        if (document.images) { 
            document[imgName].src = eval(imgName + "_on.src"); 
        } 
} 
function dsleave(imgName) { 
        if (document.images) { 
            document[imgName].src = eval(imgName + "_off.src"); 
        } 
}