简单的表单验证

Question

POST #1

如何验证这个简单的表单（检查空字段字符串）？

                <p>Please select your Gift Certificate amount below. Please also enter your name and the Gift Certificate recipient's name. Once you click 'Buy Now' you will be sent to our Paypal site to complete the purchase.</p>

                    <form action="https://www.paypal.com/cgi-bin/webscr" method="post">
        <input type="hidden" name="cmd" value="_s-xclick">
        <input type="hidden" name="hosted_button_id" value="sdsafsdafsadfdsafsdafsadfsadfsadfasdfsadfsdaf">
        <table width="100%">
        <tr>
            <td width="130"><input type="hidden" name="on0" value="Amount"><p>Amount</p></td>
            <td><select name="os0">
            <option value="Option 1">$20.00</option>
            <option value="Option 2">$50.00</option>
            <option value="Option 3">$100.00</option>
            </select></td>
        </tr>
        <tr>
            <td><input type="hidden" name="on1" value="To:"><p>To (Full Name):</p></td>
            <td><input type="text" name="os1" maxlength="60" size="30"></td>
        </tr>
        <tr>
            <td><input type="hidden" name="on2" value="From:"><p>From (Full Name):</p></td>
            <td><input type="text" name="os2" maxlength="60" size="30"></td>
        </tr>
        </table>

        <table width="100%" style="margin-top: 10px;">
            <tr>
                <td><input type="hidden" name="currency_code" value="CAD">
        <p><input type="image" src="BUTTON.jpg" border="0" name="submit" alt="PayPal - The safer, easier way to pay online!"></p>
        <img alt="" border="0" src="https://www.paypal.com/en_US/i/scr/pixel.gif" width="1" height="1"></td>
                <td align="right"><img src="../paypal_logo.jpg" alt="PayPal" /></td>
            </tr>
        </table>
        </form>

POST #2

函数 validate_form() { 有效=真；

    if ( document.GiftForm.os1.value == "" )
    {
        alert ( "Please fill in the 'Your Name' box." );
        valid = false;
    }
    return valid;
}

-=-=-=-= 表格

        <form action="https://www.paypal.com/cgi-bin/webscr" method="post" method="GiftForm" onsubmit="validate_form( )">
        <input type="hidden" name="cmd" value="_s-xclick">
        <input type="hidden" name="hosted_button_id" value="sdsafsdafsadfdsafsdafsadfsadfsadfasdfsadfsdaf">
        <table width="100%">
        <tr>
            <td width="130"><input type="hidden" name="on0" value="Amount"><p>Amount</p></td>
            <td><select name="os0">
            <option value="Option 1">$20.00</option>
            <option value="Option 2">$50.00</option>
            <option value="Option 3">$100.00</option>
            </select></td>
        </tr>
        <tr>
            <td><input type="hidden" name="on1" value="To:"><p>To (Full Name):</p></td>
            <td><input type="text" name="os1" maxlength="60" size="30"></td>
        </tr>
        <tr>
            <td><input type="hidden" name="on2" value="From:"><p>From (Full Name):</p></td>
            <td><input type="text" name="os2" maxlength="60" size="30"></td>
        </tr>
        </table>

        <table width="100%" style="margin-top: 10px;">
            <tr>
                <td><input type="hidden" name="currency_code" value="CAD">
        <p><input type="image" src="BUTTON.jpg" border="0" name="submit" alt="PayPal - The safer, easier way to pay online!"></p>
        <img alt="" border="0" src="https://www.paypal.com/en_US/i/scr/pixel.gif" width="1" height="1"></td>
                <td align="right"><img src="../paypal_logo.jpg" alt="PayPal" /></td>
            </tr>
        </table>
        </form>

Answer 1

jQuery 是一种选择吗？有一个非常好的验证工具 http://docs.jquery.com/Plugins/Validation

Answer 2

一些提示应该可以帮助您继续。

添加提交事件处理程序：

<form action="https://www.paypal.com/cgi-bin/webscr" method="post" onsubmit="return validate()">

为您想要获取的输入字段提供 ID。

<input id="currency_code" type="hidden" name="currency_code" value="CAD">

编写验证代码，如果不想提交，return false。

<script type="text/javascript">

    function validate() {

        var currencyCode = document.getElementById("currency_code");

        var ok = currencyCode.value !== '';

        return ok;

    }

</script>

Answer 3

为您的表格命名（GiftForm）

    <script type="text/javascript">
    function validate_form ( )
    {
        valid = true;

        if ( document.GiftForm.os1.value == "" )
        {
            alert ( "Please fill in the 'Your Name' box." );
            valid = false;
        }

        return valid;
    }
</script>

Answer 4

这是一个简单的教程以及演示和源代码，希望这对您有用，一切顺利！
http://gonga.in/simple-javascript-form-validation/