jQuery is not loading properly when onclick event

I want to implement, when clicked the label, should generate one multiple select element like in which many users are listed

<label class="control-label font_clr" onclick="DropDownTranformParticipantPerson('<?php  echo @$task_id ?>')">Participants :</label>

 function DropDownTranformParticipantPerson(){
    document.getElementById("participantLabel").remove();
    document.getElementById("participantParent").innerHTML='<select multiple="multiple" id="assigned_tos" name="assigned_to[]" style="width: 100%" class="select_multi"> <optgroup label="<?= lang('admin_staff') ?>"> <?php $query = $this->db->query("SELECT u.*, b.user_id, b.fullname,b.lastname FROM tbl_users u JOIN tbl_account_details b ON u.user_id = b.user_id where activated!='0' and u.role_id='3'|| u.role_id='1' order by b.fullname ASC");
        foreach ($query->result() as $row)
          {
            ?> <option value="<?php echo $row->user_id; ?>"><?php echo $row->fullname . ' '; ?><?php echo $row->lastname; ?></option><?php } ?></optgroup> </select>' ;
     isClickTaskParticipantAnyWhere=true;
 }

whenever I click on label it should generate one select (mulitple user can add) but it only works when i call DropDownTranformParticipantPerson function (without any click event ) example :

DropDownTranformParticipantPerson()// i call here
 function DropDownTranformParticipantPerson(){
    document.getElementById("participantLabel").remove();
    document.getElementById("participantParent").innerHTML='<select multiple="multiple" id="assigned_tos" name="assigned_to[]" style="width: 100%" class="select_multi"> <optgroup label="<?= lang('admin_staff') ?>"> <?php $query = $this->db->query("SELECT u.*, b.user_id, b.fullname,b.lastname FROM tbl_users u JOIN tbl_account_details b ON u.user_id = b.user_id where activated!='0' and u.role_id='3'|| u.role_id='1' order by b.fullname ASC");
        foreach ($query->result() as $row)
          {
            ?> <option value="<?php echo $row->user_id; ?>"><?php echo $row->fullname . ' '; ?><?php echo $row->lastname; ?></option><?php } ?></optgroup> </select>' ;
     isClickTaskParticipantAnyWhere=true;
 }

but any event occurd like in this it needs to be done on onclick event.

<label class="control-label font_clr" onclick="DropDownTranformParticipantPerson('<?php  echo @$task_id ?>')">Participants :</label>
function DropDownTranformParticipantPerson(){
        document.getElementById("participantLabel").remove();
        document.getElementById("participantParent").innerHTML='<select multiple="multiple" id="assigned_tos" name="assigned_to[]" style="width: 100%" class="select_multi"> <optgroup label="<?= lang('admin_staff') ?>"> <?php $query = $this->db->query("SELECT u.*, b.user_id, b.fullname,b.lastname FROM tbl_users u JOIN tbl_account_details b ON u.user_id = b.user_id where activated!='0' and u.role_id='3'|| u.role_id='1' order by b.fullname ASC");
            foreach ($query->result() as $row)
              {
                ?> <option value="<?php echo $row->user_id; ?>"><?php echo $row->fullname . ' '; ?><?php echo $row->lastname; ?></option><?php } ?></optgroup> </select>' ;
         isClickTaskParticipantAnyWhere=true;
     }

However some jQuery is missing while performing onclick event so that it is not working like previously