如何使用PHP/Javascript生成带有按钮的动态div？

大家好，我想用按钮生成这个div

question

，但问题是这个div是动态的。这是我的密码。按钮还没有javascript代码，因为我还不知道怎么做

surveycontent.php

    <div id="question">

              </div> 

       <div class="col-md-2">
       <input type="submit" name="addsection" class="btn btn-default" value="Add Section" id="addsection" />

       </div>

    <script>

        function load_questions(){

            var xmlhttp=new XMLHttpRequest();
            xmlhttp.open("GET","ajax.php??main=1&subcategory="+document.getElementById("subcategorydd").value +"&cnt="+document.getElementById("q_num").value,false);
            xmlhttp.send(null);
            document.getElementById("question").innerHTML=xmlhttp.responseText;


        }
</script>

<?php
$con = mysqli_connect("server","username","","password") or die ("Cannot connect to the database!");

$subcat=isset($_GET["subcategory"])?$_GET["subcategory"]:"";

if($subcat !="") {

    $query=mysqli_query($con, "SELECT * FROM question WHERE question_subcat = $subcat ");
    echo "<select>";
    while($row=mysqli_fetch_array($query))
    {
        echo "<option value='$row[question_id] selected'>" ; echo $row["questiontitle"]; echo "</option>";
    }
    echo "</select>";

}



?>

函数加载_问题（）{
var xmlhttp=new XMLHttpRequest（）；
xmlhttp.open（“GET”、“ajax.php？？main=1&subcategory=“+document.getElementById（“subcategory dd”）.value+”&cnt=“+document.getElementById（“q_num”）。value，false）；
xmlhttp.send（空）；
document.getElementById（“问题”）.innerHTML=xmlhttp.responseText；
}

php这是surveycontent.php中div id后面的代码

    <div id="question">

              </div> 

       <div class="col-md-2">
       <input type="submit" name="addsection" class="btn btn-default" value="Add Section" id="addsection" />

       </div>

    <script>

        function load_questions(){

            var xmlhttp=new XMLHttpRequest();
            xmlhttp.open("GET","ajax.php??main=1&subcategory="+document.getElementById("subcategorydd").value +"&cnt="+document.getElementById("q_num").value,false);
            xmlhttp.send(null);
            document.getElementById("question").innerHTML=xmlhttp.responseText;


        }
</script>

<?php
$con = mysqli_connect("server","username","","password") or die ("Cannot connect to the database!");

$subcat=isset($_GET["subcategory"])?$_GET["subcategory"]:"";

if($subcat !="") {

    $query=mysqli_query($con, "SELECT * FROM question WHERE question_subcat = $subcat ");
    echo "<select>";
    while($row=mysqli_fetch_array($query))
    {
        echo "<option value='$row[question_id] selected'>" ; echo $row["questiontitle"]; echo "</option>";
    }
    echo "</select>";

}



?>

---

在何处调用函数
加载问题
？能否添加代码段。。