输入框的隐藏与显示，实用性还是非常强的input框的隐藏显示

<input type="button" value="隐藏" onclick="csan(did,'none')"><input type="button" value="显示" onclick="csan(did,'')"><input id="did"><br><input type="button" value="隐藏" onclick="csan(dis,'none')"><input type="button" value="显示" onclick="csan(dis,'')"><input id="dis"><script>function csan(obj,sta){eval("obj.style.display=\""+sta+"\"");}</script>