if(document.images){
mba_info_on= new Image();
mba_info_on.src="/graphics/nav/mba_info_on.gif"
mba_info_off= new Image();
mba_info_off.src="/graphics/nav/mba_info_off.gif"
lawhelp_on= new Image();
lawhelp_on.src="/graphics/nav/lawhelp_on.gif"
lawhelp_off= new Image();
lawhelp_off.src="/graphics/nav/lawhelp_off.gif"
prof_programs_on= new Image();
prof_programs_on.src="/graphics/nav/prof_programs_on.gif"
prof_programs_off= new Image();
prof_programs_off.src="/graphics/nav/prof_programs_off.gif"
pub_programs_on= new Image();
pub_programs_on.src="/graphics/nav/pub_programs_on.gif"
pub_programs_off= new Image();
pub_programs_off.src="/graphics/nav/pub_programs_off.gif"
search_on= new Image();
search_on.src="/graphics/nav/search_on.gif"
search_off= new Image();
search_off.src="/graphics/nav/search_off.gif"
login_on= new Image();
login_on.src="/graphics/nav/login_on.gif"
login_off= new Image();
login_off.src="/graphics/nav/login_off.gif"
logout_on= new Image();
logout_on.src="/graphics/nav/logout_on.gif"
logout_off= new Image();
logout_off.src="/graphics/nav/logout_off.gif"
}

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

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