if (document.images) {       
            img21up = new Image();      
            img21up.src = "img/b_shokuin.gif"; 
            img22up = new Image();      
            img22up.src = "img/b_map.gif"; 
            img23up = new Image();      
            img23up.src = "img/b_bbs.gif"; 
            img24up = new Image();      
            img24up.src = "img/b_guest.gif"; 
            img25up = new Image();      
            img25up.src = "img/b_info.gif"; 
            img26up = new Image();
            img26up.src = "img/b_now.gif"; 
	   img27up = new Image();
            img27up.src = "img/b_newyear.gif"; 
	   img28up = new Image();
            img28up.src = "img/b_meeting.gif"; 

            img21dn = new Image();      
            img21dn.src = "img/b_shokuin2.gif"; 
            img22dn = new Image();      
            img22dn.src = "img/b_map2.gif"; 
            img23dn = new Image();      
            img23dn.src = "img/b_bbs2.gif"; 
            img24dn = new Image();      
            img24dn.src = "img/b_guest2.gif"; 
            img25dn = new Image();      
            img25dn.src = "img/b_info2.gif"; 
            img26dn = new Image();
            img26dn.src = "img/b_now2.gif"; 
	   img27dn = new Image();
            img27dn.src = "img/b_newyear2.gif"; 
	   img28dn = new Image();
            img28dn.src = "img/b_meeting2.gif"; 
        }



// Function to 'activate' images.
function imgOn(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "dn.src");
        }
}

// Function to 'deactivate' images.
function imgOff(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "up.src");
        }
}

function shokuinMouseOver(){
        imgOn('img21');
}

function shokuinMouseOut(){
        imgOff('img21');
}

function mapMouseOver(){
        imgOn('img22');
}

function mapMouseOut(){
        imgOff('img22');
}

function bbsMouseOver(){
        imgOn('img23');
}

function bbsMouseOut(){
        imgOff('img23');
}

function guestMouseOver(){
        imgOn('img24');
}

function guestMouseOut(){
        imgOff('img24');
}

function infoMouseOver(){
        imgOn('img25');
}

function infoMouseOut(){
        imgOff('img25');
}

function attMouseOver(){
        imgOn('img26');
}

function attMouseOut(){
        imgOff('img26');
}


function newyearMouseOver(){
        imgOn('img27');
}

function newyearMouseOut(){
        imgOff('img27');
}

function meetingMouseOver(){
        imgOn('img28');
}

function meetingMouseOut(){
        imgOff('img28');
}