last='skrypt7'; 
function show(what){ 
ie=document.all? true:false; 
moz=document.getElementById && !document.all? true:false; 
if(ie){ 
el=document.all[what]; 
if(el.style.display=='none'){ 
document.all[last].style.display='none'; 
el.style.display='block'; 
last=what; 
} else { el.style.display='none'; } 
} 
else if(moz){ 
el=document.getElementById(what); 
if(el.style.display=='none'){ 
document.getElementById(last).style.display='none'; 
el.style.display='block'; 
last=what; 
} else { el.style.display='none'; } 
} 
}