关于onfocus和onblur的问题习题问题
<head>
.red{border:1px solid red;}
</head>
<body>
姓名：<input type="text"><span></span>
</body>
<script type="text/javascript">
var name=document.getElementsByTagName("Input")[0];
var tip=document.getElementsByTagName("span")[0];
function onfocusFn(){
if(this.value==""){
tip.innerHTML="请输入您的姓名";
}else{
tip.value="";
}
}
function onblurFn(){
if(this.value==""){
tip.innerHTML="用户名不能为空";
this.style.className="red";
}else{
tip.value="";
this.removeAttribute("class");
}
}
name.onfocus=onfocusFn;
name.onblur=onblurFn;
</script>
请指教哪里出错了，好烦啊。。。速速帮忙解答。
丛从绿草浏览 994回答 1
1回答
-
码农2号
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Document</title> <style> .red{border:1px solid red;} </style> </head> <body> 姓名：<input type="text" id="inp"><span></span> <script type="text/javascript"> // var name=document.getElementsByTagName("input")[0]; var inp=document.getElementById('inp') var tip=document.getElementsByTagName("span")[0]; function onfocusFn(){ if(this.value==""){ tip.innerHTML="请输入您的姓名"; }else{ tip.innerHTML=""; } } function onblurFn(){ if(this.value==""){ tip.innerHTML="用户名不能为空"; this.classList.add('red'); }else{ tip.innerHTML=""; this.classList.remove('red'); } } inp.onfocus=onfocusFn; inp.onblur=onblurFn; </script> </body> </html>
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相关分类
JavaScript