怎么显示如图所示的结果


html>
<html>
    <head>
        <meta charset="utf-8">
        <title>title>
        <script type="text/javascript">
            function{
                var yhm=document.getElementById("yonghuming").value
                var mm=document.getElementById("mima").value
                var qrmm=document.getElementById("querenmima").value
                
            }
        script>
    head>
    <body>
        <table>
            <tr>
                <td>用户名td>
                <td><input type="text" id="yonghuming"/>td>
                <td id="userlength">首字符必须为字母，长度在6-12之间td>
            tr>
            <tr>
                <td>密码td>
                <td><input type="text" id="mima"/>td>
                <td id="mm1length">密码长度为6~12，字母和数字组合td>
            tr>
            <tr>
                <td>确认密码td>
                <td><input type="text" id="querenmima"/>td>
                <td id="mm2length">请再次输入密码td>
            tr>
        table>
    body>
html>

img

使用判断语句if...else