function isHidden(oDiv){
      var vDiv = document.getElementById(oDiv);
      vDiv.style.display = (vDiv.style.display == 'block')?'none':'block';
    }


function menu(id){
var title=id;
title_array=title.split("t");
title_num=title_array[1];
var list=document.getElementById("div"+title_num);
for (i=1;i<=5;i++ ) {
document.getElementById("div"+i).style.display='none';
}
list.style.display='';
}