Question

我有一个搜索框，其默认值为“搜索”，我需要编写一些javascript来检查搜索框中的值是“搜索”还是空，然后我不应该发送请求而我需要显示“请输入关键字”`

这是代码

    <div id="search">
    <form action="/" style="" method="post" name="searchForm" id="searchForm" onSubmit="grabSearch();">
    <img src="/images/bg_search_left.jpg" id="search_box_left" width="5" height="32" alt="" />
    <input id="search_box" type="text" value="Search"  onblur="if (this.value == '') {this.value = 'Search';}"  onfocus="if (this.value == 'Search') {this.value = '';}"/>
    <input type="image" id="search_arrow" src="/images/bg_search_right.jpg" width="34" height="32" />
    <input type="hidden" name="_page" value="SEARCH" />
    <input type="hidden" name="_action" value="SEARCH" />
    <input type="hidden" name="searchTerm" value="" />
    </form>
    </div>



    function grabSearch(){

    var search=document.getElementById('search_box').value;
    if(search="Search"||search=""){
        document.getElementById('search_box').value="Please Enter a keyword"
    }
    search=encodeSearch(search);
    document.forms['searchForm'].searchTerm.value = search;
 }

在表单提交上，我正在检查它并显示消息“请输入关键字”。虽然消息显示在文本字段中但请求已发送（我不想发生）以及文本字段的焦点我想要消息（请输入关键字）也是如此

Answer 1

除了Jeaffrey's answer之外，您没有使用正确的比较运算符。它应该是：

if(search === "Search" || search === ""){
    document.getElementById('search_box').value="Please Enter a keyword";
    return false;
}

在更改之后，您需要从onSubmit返回该值 -

<form action="www.google.com" style="" method="post" name="searchForm" id="searchForm" onsubmit="return grabSearch();">

Answer 2

您是否尝试过返回false？

if(search == "Search" || search == ""){
    document.getElementById('search_box').value="Please Enter a keyword";
    return false;
}

验证搜索问题的文本字段

2 个答案: