<style type="text/css">
span{border:#999 solid 1px; padding:3px; border-radius:6px; -moz-border-radius:6px; -webkit-border-radius:6px;}
div#show{ margin:10px 0 0 0; padding:5px; border:#999 dashed 1px;}
</style>

<script type='text/javascript'>
function show(obj, id)
{
  var o=document.getElementById(id);
  if( o.style.display == 'none' )
  {
    o.style.display='';
    obj.innerHTML='隱藏';
  }
  else
  {
    o.style.display='none';
    obj.innerHTML='顯示';
  }
}
</script>

<span onclick='show(this, "show")'>顯示</span><br>
<div id='show' style="display:none;">按下文字按鈕後呈現內容</div>