dropdownlist - select jacascript

if($data[$i]['user_level']==1){
$sel1="selected";
}elseif($data[$i]['user_level']==2){
$sel2="selected";
}elseif($data[$i]['user_level']==3){
$sel3="selected";
}elseif($data[$i]['user_level']==4){
$sel4="selected";
}
<select class='form-control' style='width:250px' onchange=\"window.open(this.options[this.selectedIndex].value,'_self')\">
<!--<option value=\"#\">Chọn tình trạng</option>-->
<option value=\"$adminfile.php?op=shoping_user_level&id=".$data[$i]['user_id']."&status=1\" $sel1>"._LEVEL1."</option>
<option value=\"$adminfile.php?op=shoping_user_level&id=".$data[$i]['user_id']."&status=2\" style=\"color:teal\"  $sel2>Thành viên 2</option>
<option value=\"$adminfile.php?op=shoping_user_level&id=".$data[$i]['user_id']."&status=3\" style=\"color:blue\" $sel3>Thành viên 3</option>
<option value=\"$adminfile.php?op=shoping_user_level&id=".$data[$i]['user_id']."&status=4\" style=\"color:#FF0000\" $sel4>Thành viên 4</option>
</select>