php - Update multiple select box -

i have code :

<?php     if($_get["id"]){         $rezizmjena = mysqli_query($kon, "select * shops id=". $_get["id"] ." limit 1");         $redizmjena = mysqli_fetch_assoc($rezizmjena);         $fototxt = "nieuwe logo :";         $btntxt = "veranderen";     }else{         $fototxt = "kies logo :";         $btntxt = "toevoegen";     }  ?>  <div class="col-xs-12 col-sm-5">     <select class="form-control" name="slcregio[]" multiple="multiple">     <?php              $rez = mysqli_query($kon, "select * regios");             echo "<option selected disabled>kies een regio</option>";             while($red = mysqli_fetch_assoc($rez)){                 $rez1 = mysqli_query($kon, "select regios.id, shop_regio_tt.regio_id, shop_regio_tt.shop_id regios inner join shop_regio_tt on regios.id = shop_regio_tt.regio_id");                 while($red1 = mysqli_fetch_assoc($rez1)){                    if($red1["shop_regio_tt.shop_id"] == $redizmjena["id"]){                         $selected = "selected";                      }else{                         $selected = "";                      }                 }                 echo "<option value=\"". $red["id"] ."\" ". $selected .">". $red["naam"] ."</option>";              }     ?>  </select><br />   </div> 

in database have shops table (id, naam, ...), regios table (id, naam) , shop_regio_tt (id, shop_id, regio_id).

when want update item want see items have been selected. code nothing selected.

i fetch result here

 foreach ($_post["slcregio"] $regio_id){          mysqli_query($kon, "insert shop_regio_tt values(null,". $_post["izmjena"] .",". $regio_id .")");                       } 

and how update shop_regio_tt if hidden field has been send?

thanks in advance.

yes in code snippest there

if($red1["shop_regio_tt.shop_id"] == $redizmjena["id"])

i did not found variable $redizmjena.

i think should $red['id']