Javascript 提交前如何更改隐藏输入字段的值

我有一个Feedburner订阅表单，有两个按钮，一个用于每日新闻，一个用于每周新闻。问题是如何在提交之前更改名为“uri”的隐藏输入字段的值？我的解决方案不起作用

这就是我尝试使用的：

<form id="feedburner" action="https://feedburner.google.com/fb/a/mailverify"
    method="post" target="popupwindow">
    <p>
        <input autocomplete="off" value="Enter your email…"
            onblur="if (this.value == '') {this.value = 'Enter your email…';}"
            onfocus="if (this.value == 'Enter your email…') {this.value = '';}"
            type="text" name="email"/>
        <input type="hidden" name="uri"/>
        <input type="hidden" name="loc" value="en_US"/>
    </p>

    <input type="submit" value="Daily" onsubmit="document.getElementsByName('uri').value = 'androidinfodaily'; window.open('https://feedburner.google.com/fb/a/mailverify?uri=androidinfodaily', 'popupwindow'); return true" checked> 

    <input type="submit" value="Weekly" onsubmit="document.getElementsByName('uri').value = 'androidinfoweekly'; window.open('https://feedburner.google.com/fb/a/mailverify?uri=androidinfoweekly', 'popupwindow'); return true">

</form>

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已解决

我已经修复了我的代码，现在它可以工作了。这是最后一个变体：

<form id="feedburner" action="https://feedburner.google.com/fb/a/mailverify"
    method="post" target="popupwindow">
    <p>
        <input autocomplete="off" value="Enter your email…"
            onblur="if (this.value == '') {this.value = 'Enter your email…';}"
            onfocus="if (this.value == 'Enter your email…') {this.value = '';}"
            type="text" name="email"/>
        <input type="hidden" name="uri" />
        <input type="hidden" name="loc" value="en_US"/>
    </p>

    <input type="submit" value="Daily" onclick="document.getElementsByName('uri')[0].value = 'androidinfodaily'; window.open('https://feedburner.google.com/fb/a/mailverify?uri=androidinfodaily', 'popupwindow'); return true"> 

    <input type="submit" value="Weekly" onclick="document.getElementsByName('uri')[0].value = 'androidinfoweekly'; window.open('https://feedburner.google.com/fb/a/mailverify?uri=androidinfoweekly', 'popupwindow'); return true">

</form>

在表单元素上触发，而不是在提交按钮上触发，因此请使用处理程序

请注意，submit仅在表单元素上触发，而不是按钮或按钮 提交输入。（提交的是表格，而不是按钮。）

---

您可以单击按钮的事件处理程序，并将按钮类型更改为

type=“button”

，这样它就不会直接提交表单。在内部，单击处理程序将balue分配给

uri

输入，然后提交表单

HTML:

---

不要忘记第一个元素的

[0]

：

document.getElementsByName('uri')[0].value = 'androidinfodaily';

---

它也应该是

document.getElementsByName（'uri'）[0]。value

as

getElementsByName

返回一个集合

<form id="feedburner" action="https://feedburner.google.com/fb/a/mailverify" method="post" target="popupwindow">
    <p>
        <input autocomplete="off" value="Enter your email…" onblur="if (this.value == '') {this.value = 'Enter your email…';}" onfocus="if (this.value == 'Enter your email…') {this.value = '';}" type="text" name="email" />
        <input type="hidden" name="uri" />
        <input type="hidden" name="loc" value="en_US" />
    </p>
    <input type="submit" value="Daily" onclick="return beforeSubmit('androidinfodaily')" checked />
    <input type="submit" value="Weekly" onclick="return beforeSubmit('androidinfoweekly')" />
</form>

function beforeSubmit(type) {
    document.getElementsByName('uri')[0].value = type;
    window.open('https://feedburner.google.com/fb/a/mailverify?uri=' + type, 'popupwindow');
    return true
}

<form id="feedburner" action="https://feedburner.google.com/fb/a/mailverify"
    method="post" target="popupwindow">
    <p>
        <input autocomplete="off" value="Enter your email…"
            onblur="if (this.value == '') {this.value = 'Enter your email…';}"
            onfocus="if (this.value == 'Enter your email…') {this.value = '';}"
            type="text" name="email"/>
        <input type="hidden" name="uri"/>
        <input type="hidden" name="loc" value="en_US"/>
    </p>

    <input type="button" value="Daily" id="daily"> 

    <input type="button" value="Weekly" id="weekly">

</form>

$(function(){
   $('#daily').click(function(){
      $('input[name="uri"]').val('androidinfodaily');
      window.open('https://feedburner.google.com/fb/a/mailverify?uri=androidinfodaily', 'popupwindow');
      //submit form
      $('#feedburner').submit();
   });

   $('#weekly').click(function(){
    $('input[name="uri"]').val('androidinfodaily');
      window.open('https://feedburner.google.com/fb/a/mailverify?uri=androidinfoweekly', 'popupwindow');
      //submit form
      $('#feedburner').submit();
  });
});

document.getElementsByName('uri')[0].value = 'androidinfodaily';