bmain_up = new Image();           // Active images
bmain_up.src = "http://bmerc-www.bu.edu/images/main_button_u.gif";  

btools_up = new Image();
btools_up.src = "http://bmerc-www.bu.edu/images/tools_button_u.gif";  

bnew_up = new Image();
bnew_up.src = "http://bmerc-www.bu.edu/images/new_button_u.gif";  

bmap_up = new Image();
bmap_up.src = "http://bmerc-www.bu.edu/images/map_button_u.gif";  
                 
bsearch_up = new Image();
bsearch_up.src = "http://bmerc-www.bu.edu/images/search_button_u.gif";  
                 
bmain_down = new Image();          // Inactive images
bmain_down.src = "http://bmerc-www.bu.edu/images/main_button_d.gif"; 

btools_down = new Image();
btools_down.src = "http://bmerc-www.bu.edu/images/tools_button_d.gif"; 

bnew_down = new Image();
bnew_down.src = "http://bmerc-www.bu.edu/images/new_button_d.gif"; 

bmap_down = new Image();
bmap_down.src = "http://bmerc-www.bu.edu/images/map_button_d.gif"; 

bsearch_down = new Image();
bsearch_down.src = "http://bmerc-www.bu.edu/images/search_button_d.gif"; 

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

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