form表单验证提交

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>

<body>
    <form action="http://www.baidu.com" onsubmit="return toVaild()">
        <input type="text" id="ff"> <input type="submit" id="submit" value="提交" /> </form>
</body>
　　

<script language="javascript">
    function toVaild() {

        var val = document.getElementById("ff").value;
        // alert(val);

        if (val == "可以提交") {
            alert("校验成功，之后进行提交");

            return true;

        } else {
            alert("校验失败，不进行提交");

            return false;

        }

    }
</script>

</html>