php - how to increment session id variable after adding item into cart -

i working a cart item user can add multiple item cart , delete item cart using session after adding 1 item increment id 1 one on each add new item cart code working fine problem in deleting when trying delete item item tray delete 1 item here code

<?php session_start(); if(!empty($_get["action"])) { switch($_get["action"]) {    case "add":    if(!isset($_session['cart'])) {            $item_id_session = 1;            $_session['cart'] = array();      }     else         {             $count = count($_session['cart']);              $item_id_session = $count++;         }              $item = array();             $item['item_id_session']= $item_id_session ;             $item['title']=$_request['title'];             $item['length_m']  =$_request['length_m'];             $item['length_md']=$_request['length_md'];             $item['length_cm'] =$_request['length_cm'];             $item['length_cmd']=$_request['length_cmd'];             $item['width_m']=$_request['width_m'];             $item['width_md']=$_request['width_md'];             $item['width_cm']=$_request['width_cm'];             $item['width_cmd']=$_request['width_cmd'];             $item['height_m']=$_request['height_m'];             $item['height_md']=$_request['height_md'];             $item['height_cm']=$_request['height_cm'];             $item['height_cmd']=$_request['height_cmd'];             $item['weight']=$_request['weight'];             $item['weightd']=$_request['weightd'];             $item['quantity']=$_request['quantity'];             $item['image']=$_files["image"]["name"];             $target_dir = "profile_images/";             $item['image']= "profile_images/" . $_files["image"]["name"];             $imagefiletype = pathinfo($item['image'],pathinfo_extension);             $check = getimagesize($_files["image"]["tmp_name"]);          if($check !== false) {          echo "file image - " . $check["mime"] . ".";         //$uploadok = 1;          move_uploaded_file($_files["image"]["tmp_name"], $item['image']);          echo "the file ". basename( $_files["image"]["name"]). " has been uploaded.";          }            $_session['cart'][] = $item;    break;    case "remove":      if(!empty($_session["cart"])) {       foreach($_session["cart"] $k => $v) {           if($_get['item_id_session'] == $k)             unset($_session["cart"][$k]);              unset($_session['cart'][$item_id_session]);                 if(empty($_session["cart"]))             unset($_session["cart"]);        }     }     break;      } } ?> 

here delete button code

    <a href="step3.php?action=remove&id=<?php echo $item["item_id_session"];?>"class="product-title">     <span class="glyphicon glyphicon-trash pull-right"></span>     </a> 

try this.while adding items cart need use $item_id_session key.

 case "add":     if (isset($_session['cart']) && count($_session['cart']) > 0) {         $count = count($_session['cart']);         $item_id_session = $count+ 1;     } else {          $item_id_session = 1;         $_session['cart'] = array();     }                      $item = array();                     $item['item_id_session']= $item_id_session ;                     $item['title']=$_request['title'];                     $item['length_m']  =$_request['length_m'];                     $item['length_md']=$_request['length_md'];                     $item['length_cm'] =$_request['length_cm'];                     $item['length_cmd']=$_request['length_cmd'];                     $item['width_m']=$_request['width_m'];                     $item['width_md']=$_request['width_md'];                     $item['width_cm']=$_request['width_cm'];                     $item['width_cmd']=$_request['width_cmd'];                     $item['height_m']=$_request['height_m'];                     $item['height_md']=$_request['height_md'];                     $item['height_cm']=$_request['height_cm'];                     $item['height_cmd']=$_request['height_cmd'];                     $item['weight']=$_request['weight'];                     $item['weightd']=$_request['weightd'];                     $item['quantity']=$_request['quantity'];                     $item['image']=$_files["image"]["name"];                     $target_dir = "profile_images/";                     $item['image']= "profile_images/" . $_files["image"]["name"];                     $imagefiletype = pathinfo($item['image'],pathinfo_extension);                     $check = getimagesize($_files["image"]["tmp_name"]);                  if($check !== false) {                  echo "file image - " . $check["mime"] . ".";                 //$uploadok = 1;                  move_uploaded_file($_files["image"]["tmp_name"], $item['image']);                  echo "the file ". basename( $_files["image"]["name"]). " has been uploaded.";                  }                    $_session['cart'][$item_id_session] = $item;            break;            case "remove":              if(!empty($_session["cart"])) {               foreach($_session["cart"] $k => $v) {                   if($_get['item_id_session'] == $k)                     unset($_session["cart"][$k]);                }             }             break;