var current_div = 't_01';

function showDiv(div_id)
{

hideDiv(current_div);
current_div = div_id;

   if (document.getElementById && document.getElementById(div_id))
   {
   document.getElementById(div_id).style.display = 'block';
   }

}

function hideDiv(div_id)
{

   if (document.getElementById && document.getElementById(div_id))
   {
   document.getElementById(div_id).style.display = 'none';
   }

}

function toggleDiv(div_id)
{

   if (document.getElementById && document.getElementById(div_id))
   {
   var div_ref = document.getElementById(div_id).style;

      if (div_ref.display == 'none')
      {
      div_ref.display = 'block';
      }
      else if (div_ref.display == 'block' || div_ref.display == '')
      {
      div_ref.display = 'none';
      }

   }

}