javascript验证规则不起作用

时间:2013-03-28 09:54:49

标签: javascript validation

我有以下代码,验证规则不起作用,请帮忙! Web浏览器无法识别javascript代码,因为似乎没有显示活动x控件。

<HTML>
<head>
<title>Exam entry</title>

<script lanuage="javascript" type="text/javascript">

var result = true;

function validateForm() {

    var msg="";

    if (document.ExamEntry.name.value=="") {
        msg+="you must enter your name \n";
        document.ExamEntry.name.focus();
        document.getElementById('name').style.color="red";
        result = false;
    }
    if (document.ExamEntry.subject.value=="") {
        msg+("You must enter the subject \n");
        document.ExamEntry.subject.focus();
        document.getElementById('subject').style.color="red";
        result false;
    }
    if (document.ExamEntry.ExaminationNumber.value=="") {
        msg+("You must enter the Examination Number \n");
        document.ExamEntry.ExaminationNumber.focus();
        document.getElementById('ExaminationNumber').style.color="red";
        result false;
    }
    if(msg==""){
    return result;
    }

    {
    alert(msg)
    return result;
    }
}
</script>
<form>
        <input type="radio" name="qualification" value="GCSE">GCSE<br>
        <input type="radio" name="qualification" value="AS">AS<br>
        <input type="radio" name="qualification" value="A2">A2<br>
</form>
</head>

<body>
<h1>Exam Entry Form</h1>
<form name="ExamEntry" method="post" action="success.html">
<table width="50%" border="0">
    <tr>
        <td id="name">Name</td>
        <td><input type="text" name="name" /></td>
    </tr>
    <tr>
        <td id="subject">Subject</td>
        <td><input type="text" name="subject" /></td>
    </tr> 
    <tr>
        <td id="ExaminationNumber">ExaminationNumber</td>
        <td><input type="text" name="ExaminationNumber" /></td>
    </tr>
<tr>
    <td><input type="submit" name="Submit" value="Submit" onclick="return validateForm();" /></td>
    <td><input type="reset" name="Reset" value="Reset" /></td>
</tr>

</table>
</form>
</body>
</HTML>

请有人帮忙,这让我很生气!

2 个答案:

答案 0 :(得分:0)

第23和29行缺少'='符号 result false;应为result = false;

提示:您可以在浏览器的开发者控制台中检查js错误。

更新:好的,我测试时以下工作正常:

<html>
<head>
    <title>Exam entry</title>

    <script lanuage="javascript" type="text/javascript">

        var result = true;

        function validateForm() {

            var msg = "";

            if (document.ExamEntry.name.value == "") {
                msg += "you must enter your name \n";
                document.ExamEntry.name.focus();
                document.getElementById('name').style.color = "red";
                result = false;
            }
            if (document.ExamEntry.subject.value == "") {
                msg + ("You must enter the subject \n");
                document.ExamEntry.subject.focus();
                document.getElementById('subject').style.color = "red";
                result = false;
            }
            if (document.ExamEntry.ExaminationNumber.value == "") {
                msg + ("You must enter the Examination Number \n");
                document.ExamEntry.ExaminationNumber.focus();
                document.getElementById('ExaminationNumber').style.color = "red";
                result = false;
            }
            if (msg == "") {
                return result;
            }

            {
                alert(msg)
                return result;
            }
        }
    </script>
</head>

<body>
    <h1>Exam Entry Form</h1>
    <form name="ExamEntry" method="post" action="success.html">
        <table style="width: 50%;" border="0">
            <tr>
                <td id="name">Name</td>
                <td>
                    <input type="text" name="name" /></td>
            </tr>
            <tr>
                <td id="subject">Subject</td>
                <td>
                    <input type="text" name="subject" /></td>
            </tr>
            <tr>
                <td id="ExaminationNumber">ExaminationNumber</td>
                <td>
                    <input type="text" name="ExaminationNumber" /></td>
            </tr>
            <tr>
                <td>
                    <input type="submit" name="Submit" value="Submit" onclick="return validateForm();" /></td>
                <td>
                    <input type="reset" name="Reset" value="Reset" /></td>
            </tr>
        </table>
    </form>
</body>
</html>

答案 1 :(得分:-1)

您的问题中的代码段失败有几个原因。让我指出一些缺陷:

  1. 头部不应有表格
  2. document.ExamEntry无效。正确的是document.forms['ExamEntry']
  3. document.ExamEntry.subject这样的东西是不可能的。链接子节点不起作用。需要使用提供的DOM方法遍历DOM。我建议您阅读http://net.tutsplus.com/tutorials/javascript-ajax/javascript-and-the-dom-series-lesson-1/
  4. 等教程

    我修改了JavaScript并添加了jsFiddle以使验证工作。这是一个快速解决方案。我添加了一个名为getInputByName的辅助函数:

    <script type="text/javascript">
    
    function getInputByName(inputName) {
        var inputs = document.getElementsByTagName('input');
    
        for (var i = 0, ii = inputs.length, input; i < ii, input = inputs[i]; i++) {
            if (input.name === inputName) {
                return input
            }
        }
        return false;
    }
    
    
    
    function validateForm() {
    
        var result = true;
    
        var msg="";
    
        if (getInputByName('name').value=="") {
            msg+="you must enter your name \n";
            getInputByName('name').focus();
            document.getElementById('name').style.color="red";
            result = false;
        }
    
    
        if (getInputByName('subject').value=="") {
            msg+("You must enter the subject \n");
            getInputByName('subject').focus();
            document.getElementById('subject').style.color="red";
            result = false;
        }
    
        if (getInputByName('ExaminationNumber').value=="") {
            msg+("You must enter the Examination Number \n");
            getInputByName('ExaminationNumber').focus();
            document.getElementById('ExaminationNumber').style.color="red";
            result = false;
        }
    
        if (msg == ""){
            return result;
        } else {
            alert(msg)
            return result;
        }
    }
    </script>