<input type="text" name="username" value="" id="username" maxlength="20" onblur="if(this.value=='')this.value='请输入用户名';this.style.color='#999' " onfocus="if(this.value.substring(0,2)=='请输')this.value=''; this.style.color='#333'" value="请输用户名"/>
<input type="text" name="username" value="" id="username" maxlength="20" onblur="if(this.value=='')this.value='请输入用户名';this.style.color='#999' " onfocus="if(this.value.substring(0,2)=='请输')this.value=''; this.style.color='#333'" value="请输用户名"/>