如何在特定單選按鈕被選中時調用JavaScript？

Question

<div id="dept-or-user-div" class="panel" style="padding-bottom:10px;"> 
    <h3 class="div-title">Select Alert Recipients</h3> 
    <div class="recipient-error" style="display:none;"><p style="padding-top:10px; color:#f00;">Please select at least one recipient</p></div> 

    <p> 
     <input type="radio" checked value="dept" name="user-or-dept">Department</input> 
     <input type="radio" value="user" name="user-or-dept">User</input> 
     <input type="radio" value="both" name="user-or-dept">Both</input> 
    </p> 
    <div class="department-select" class="dept"> 
     <p><label for="department-choice">Department:</label> 
     <select name="department-choice" id="department-choice"> 
      <option></option> 
      <?php 
       echo get_departments(); 
      ?> 
     </select></p> 
    </div><!--end #department-select--> 
    <div class="user-select user" > 
     <p><label for="user-choice">User:</label> 

     <select name='user-choice' id="user-choice"> 
      <option></option> 
      <?php 
       echo get_users('option'); 
      ?> 
     </select></p> 

    </div><!--end #user-select--> 

</div><!--end #dept-or-user-div--> 

在這裏，我有三個單選按鈕

1. 系（部下拉）
2. 用戶（用戶下拉）
3. 雙方（用戶和部門dropwon）

而且我想要什麼當單選按鈕的值爲「Both」，即第三個單選按鈕被選中時，我想調用一個js函數並根據部門值動態填充用戶下拉列表。我怎樣才能做到這一點？

Answer 1

給它一個id，

<input type="radio" id="both" value="both" name="user-or-dept">Both</input> 

然後，使用jQuery ....做這樣的事情......

$('input#both').change(function(){ 

if($(this).is(':checked')) { 

//do your ajax call here to retrieve values from database based on whatever criteria 
//and populate the result wherever you want 
$.ajax({ 
url: "getdept.php", 
type: "POST", 
data: {type: "both"}, 
dataType: "html", 
success: function(result){ 
    $('#department-choice').html(result); 
} 
}); 

}} 

在PHP文件

然後，像...

$both = mysql_real_escape_string($_POST['type']); 

$sql = "SELECT * FROM table WHERE dept = $both"; 
//dunno what your query will be, because I have no idea of your database 
$res = mysql_query($sql); 
while($row = mysql_fetch_array($res)){ 
    echo "<option>".$row['dept']."</option>"; 
} 

這形式將輸出...

<option>blah blah</option> 
<option>blah blah</option> 
<option>blah blah</option> 

這將插入到select下拉列表中，上面顯示了ajax。