输入框焦点

onfocus="if (value =='输入账号'){value =''}" onblur="if (value ==''){value='输入账号'}" value="输入账号"

<input type="password" name="textfield2" id="userpwd" class="txt_input" onfocus="if (value ==&#39;******&#39;){value =&#39;&#39;}" onblur="if (value ==&#39;&#39;){value=&#39;******&#39;}" value="******">