function show_sub_div(div_id) {
    document.getElementById('sub_div_1').style.display = 'none';
    document.getElementById('sub_div_2').style.display = 'none';
    document.getElementById('sub_div_3').style.display = 'none';
    document.getElementById('sub_div_4').style.display = 'none';
    document.getElementById(div_id).style.display = 'block';
HoldMenus();
return false;
}
var holdit = false;
function HoldMenus() { holdit = true; }
function HideMenus() { setTimeout("HideOpenMenus()",1000);holdit = false; }
function HideOpenMenus() { 
if (holdit == false)
   {
show_sub_div('sub_div_0');
   }
}