input输入框内的提醒方式

/*input输入框内的提醒方式*//*注意不要用name作变量，chrome把它当关键字了。*/var username=document.getElementById("id_username");username.onclick =username.onfocus= function(){if(this.value!="请输入账号") return;this.value="";this.style.color="black";}username.onblur = function(){if(this.value != "") return;this.value="请输入账号";this.style.color="#666666";}