form表单提交案例 document.getElementById(" ") 

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
        <script type="text/javascript">
            function form_submit(){
                var uname=document.getElementById("uname");
                if (uname.value=="") {
                    alert("用户名不允许为空.");
                    return false;
                }
                if (uname.value.length<3||uname.value.length>6) {
                    alert("用户名长度为3~6位");
                    return false;
                }
                for (var i=0;i<uname.value.length;i++) {
                    if (uname.value.charAt(i)>0) {
                        alert("用户名包含数字不合法");
                        return false;
                    }
                }
                
                
                
                var email=document.getElementById("email");
                if (email.value=="") {
                    alert("邮箱不允许为空.");
                    return false;
                }
                var str1=email.value.indexOf("@");
                var str2=email.value.indexOf(".");
                if (str1==-1||str2==-1) {
                    alert("邮箱格式不合法.");
                    return false;
                }
                
                
                
                var mima=document.getElementById("mima");
                if (mima.value=="") {
                    alert("密码不允许为空.");
                    return false;
                }
                if (mima.value.length<6) {
                    alert("密码长度不少于6位");
                    return false;
                }
                
                
                
                
                return true;
            }
        </script>
    </head>
    <body>
        <form action="http://www.baidu.com" method="get" onsubmit="return form_submit()">
            Username:<input id="uname" type="text" name="uname" /><br />
            Email:<input id="email" type="text" name="email" /><br />
            Password:<input id="mima" type="password" name="mima" /><br />
            <input type="submit" value="提交"/>
            
        </form>
    </body>
</html>

 运行：

 

posted @ 2019-05-31 11:13  南山下的采药人  阅读(1490)  评论(0)    收藏  举报