我想创建一个动态下拉列表（不带有oci / mysql）

Question

i want to create a dynamic dropdown showing SDE when DE is selected My problem is that though the list of DE is displayed (snapshot attached) but i don't get SDE (As i think that I am unable to pass the onclick value following line in code:--------- echo ''.$jto.'';)

I have tried a lot of options but none worked

    enter code here

    <form name="form1" action="" method="post">
<table>
<tr>
<td> select de</td>
<td><select id="dedd" onChange="change_de()">
<option>select</option>
<?php


    $jtosql="SELECT DISTINCT DE_OD FROM cdr_phone_control";
    $jtoqr=odbc_exec($conn, $jtosql);
    while(odbc_fetch_row($jtoqr))
                { 
            $jto=odbc_result($jtoqr,"DE_OD");

            echo '<option value="'.$jto.'">'.$jto.'</option>';
            //echo "<option>".$jto."</option>";
            /*?><option value="<?php echo $jto; ?>">"<?php".$jto."?></option><?php
            ?><option><?php echo ."$jto." ?></option><?php
            ?><option value="<?php echo $jto ?>"><?php echo "$jto"; ?></option><?php
            ?><a href="test52.php?page=<?php echo $b;?>" style="text-decoration:none"><input type="submit" value="<?php echo $b." "; ?>"</a><?php*/
            }           
$page=$_GET["dedd"];            
            ECHO $jto;
        echo $jtoqr;
        echo $page;
    /*?><a href="test52.php?page=<?php echo $b;?>" style="text-decoration:none"><input type="submit" value="<?php echo $b." "; ?>"</a><?php*/       
?>
</select>
</td></tr>

<tr><td>select sde</td>
<td>
<div id="sde">
<select><option>select</option></select></div>
</td></tr>
</table>
</form>
<script type="text/javascript">
function change_de()
{
var xmlhttp=new XMLHttpRequest();
xmlhttp.open("GET","ajax.php?de="+document.getElementById("dedd").value,false); 
xmlhttp.send(null);
//alert(xmlhttp.responseText);
document.getElementById("sde").innerHTML=xmlhttp.responseText;

}
</script>

/*AJAX.PHP STARTS HERE */
$de=$_GET['dedd'];
//$staff=$_POST['callLL'];
if($de!="")
{
$jtosql="SELECT DISTINCT SDO_OD FROM cdr_phone_control where de_od='$de'";
    $jtoqr=odbc_exec($conn, $jtosql);
    echo "<select>";
    while(odbc_fetch_row($jtoqr))
                { 
            $jto=odbc_result($jtoqr,"SDO_OD");
            //echo "<option>".$jto."</option>";
            /*?><option value="<?php echo $jto; ?>">"<?php".$jto."?></option><?php
            ?><option><?php echo ."$jto." ?></option><?php*/
            ?><option value="<?php echo $jto ?>"><?php echo "$jto"; ?></option><?php
            }
echo "</select>";   

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