AJAX 表单正在向自身提交？

我不知道今晚发生了什么，但我似乎无法让 AJAX 工作。提交表单后，它会使用 URL 中的值刷新页面。我正在使用具有提交处理程序的验证插件，但它仍然会刷新。我以前用过这个方法，没有出现任何问题。看看这里的页面，让我知道您的想法：

<div class="demo_content" style="display:none">
    <form id="contact_form">
        <span class="inputSpan">
            <input value="" class="input input1" title="First name" id="firstName" name="firstName" type="text" />
        </span>
        <span class="inputSpan">
            <input value="" class="input input2" title="Last name" id="lastName" name="lastName" type="text" />
        </span>
        <span class="inputSpan">
            <input value="" class="input input2" title="Email" id="email" name="email" type="text" />
        </span>
        <span class="inputSpan">
            <textarea type="text" id="message" name="message" title="Message" class="input textArea" ></textarea>
        </span>

        <span class="inputSpan">
            <input type="submit" name="submit" class="button" id="submit_btn" value="Send" />
        </span>
        <div id="contact_ajax_wrap">
            <div id="contact_ajax_gif" style="display:none;"><img src="http://www.jacobsmits.com/images/main/ajax-loader-black.gif" width="32" height="32" /></div>
            <div id="contact_ajax_success" style="display:none">Thanks! I'll get back to you shortly.</div>
        </div>
    </form>

<script type="text/javascript">
    //This script will handle the email form
    $(window).load(function() {
        $('#contact_form').placeholderRX({textColor: '#999', hoverColor: '#FBFBFB', addClass: 'yourFormInputText'});
    });
    $(".button").click(function() {
        var dataString = "fname=" + $("#firstName").val();
        alert(dataString);
        $.ajax({
            type: "POST",
            url: "http://www.jacobsmits.com/demos/scripts/contact_form.php",
            data: dataString,
            success: function(result) {
                if(result == "Success"){
                    alert("Success");
                }else{
                    alert("Fail");
                }
            }
        });
    });
</script>

您需要取消提交按钮的默认行为（提交表单而不是ajax）。
可以用以下方法完成preverntDefault()在事件对象上或与return false;

   $(".button").click(function(e) {
        var dataString = "fname=" + $("#firstName").val();
        alert(dataString);
        $.ajax({
            type: "POST",
            url: "http://www.jacobsmits.com/demos/scripts/contact_form.php",
            data: dataString,
            success: function(result) {
                if(result == "Success"){
                    alert("Success");
                }else{
                    alert("Fail");
                }
            }
        });
        return false; /// <=== that was missing.
        e.preventDefault(); /// Or this.
    });

有一个提交事件，所以最好监听这个事件而不是点击按钮：

   $("#contact_form").submit(function(e) {
        var dataString = "fname=" + $("#firstName").val();
        alert(dataString);
        $.ajax({
            type: "POST",
            url: "http://www.jacobsmits.com/demos/scripts/contact_form.php",
            data: dataString,
            success: function(result) {
                if(result == "Success"){
                    alert("Success");
                }else{
                    alert("Fail");
                }
            }
        });
        return false; /// <=== that was missing.
        e.preventDefault();  /// Or this.
    });