HTML

      <div class="con">
        <div class="top">
            <p><img src="logo.jpg"></p>
        </div>
        <div class="bottom">
            <p>
                用戶名:<input type="text" placeholder="請輸入用戶名">
                <span></span>
            </p>
            <p>
                密碼:<input type="password" placeholder="請輸入密碼">
                <span></span>
            </p>
            <p>
                郵箱:<input placeholder="請輸入郵箱">
                <span></span>
            </p>
            <p>
                請確認(rèn)密碼:<input type="password" placeholder="請輸入密碼">
                <span></span>
            </p>
            <p>
                請輸入手機(jī)號:<input type="text" placeholder="請輸入密碼">
                <span></span>
                <img src="sprite.png"/>
            </p>
        </div>
    </div>

css樣式

    <style type="text/css">
        *{
            padding: 0;
            margin: 0;
        }
        .con{
            margin:100px auto;
            height:500px;
            width:500px;
            border:1px solid #000;
        }
        .top{
            padding-bottom: 30px;
            border-bottom: 1px solid #000;
        }
        .top>p{
            text-align: center;
            margin-top: 30px;   
        }
        .bottom>p{
            margin-top:10px; 
        }
    </style>

js樣式

          <script>
        var input=document.querySelectorAll('input');
        console.log(input);
        
      （用戶名）
        input[0].onfocus=function(){
            this.nextElementSibling.innerHTML='支持中文磁滚、字母担映、數(shù)字的2-18個(gè)字符';
            
        }
        
        input[0].onblur=function(){
            var reg=/^[\u4e00-\u9fa5a-zA-Z0-9]{2,18}$/;
            var result=reg.test(input[0].value);
            if(result==true){
                this.nextElementSibling.innerHTML="通過";
            }else{
                this.nextElementSibling.innerHTML="格式錯(cuò)誤";
            }
        }
        
        
      （  密碼）
        input[1].onfocus=function(){
            this.nextElementSibling.innerHTML='支持中文单匣、字母、數(shù)字的2-18個(gè)字符'
        }
        
        input[1].onblur=function(){
            var reg=/^[\u4e00-\u9fa5a-zA-Z0-9]{2,18}$/;
            var result=reg.test(input[1].value);
            if(result==true){
                this.nextElementSibling.innerHTML="通過";
            }else{
                this.nextElementSibling.innerHTML="格式錯(cuò)誤";
            }
        }
        
       （ 郵箱）
        input[2].onfocus=function(){
            this.nextElementSibling.innerHTML='支持123.165.qq等郵箱'
        }
        
        input[2].onblur=function(){
            var reg=/^\w{3,11}@(123|165|qq).com$/;
            var result=reg.test(input[2].value);
            if(result==true){
                this.nextElementSibling.innerHTML="通過";
            }else{
                this.nextElementSibling.innerHTML="格式錯(cuò)誤";
            }
        }
         input[3].onfocus=function(){
            this.nextElementSibling.innerHTML='請?jiān)俅屋斎肽拿艽a';
         }
         input[3].onblur=function(){
            
            if(input[1].value==input[3].value){
                this.nextElementSibling.innerHTML="通過";
            }else{
                this.nextElementSibling.innerHTML="不通過";
            }
        }
        input[4].onfocus=function(){
            this.nextElementSibling.innerHTML='請輸入您的手機(jī)號';
        }
        input[4].onblur=function(){
            var ref=/^1[3456789]\d{9}$/;
            var cer=ref.test(input[4].value);
            if(cer){
                this.nextElementSibling.innerHTML='通過';
            }else{
                
                this.nextElementSibling.innerHTML='請輸入正確格式的手機(jī)號';
                this.nextElementSibling.nextElementSibling.innerHTML.display='none';
            }
        }
    </script>