diff --git a/lab-python-error-handling.ipynb b/lab-python-error-handling.ipynb
index f4c6ef6..276672e 100644
--- a/lab-python-error-handling.ipynb
+++ b/lab-python-error-handling.ipynb
@@ -72,11 +72,211 @@
     "\n",
     "4. Test your code by running the program and deliberately entering invalid quantities and product names. Make sure the error handling mechanism works as expected.\n"
    ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "id": "464b1353",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Step 1:\n",
+    "def initialize_inventory(products):\n",
+    "    inventory = {}\n",
+    "    for product in products:\n",
+    "        valid_quantity = False\n",
+    "        while not valid_quantity:\n",
+    "            try:\n",
+    "                quantity = int(input(f\"Enter the quantity of {product}s available: \"))\n",
+    "                if quantity < 0:\n",
+    "                    raise ValueError(\"Invalid quantity! Please enter a non-negative value.\")\n",
+    "                valid_quantity = True\n",
+    "            except ValueError as error:\n",
+    "                print(f\"Error: {error}\")\n",
+    "        inventory[product] = quantity\n",
+    "    return inventory\n",
+    "    "
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "id": "b4154ae6",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Step 2:\n",
+    "def calculate_total_price(customer_orders):\n",
+    "    total_price = 0.0\n",
+    "    \n",
+    "    for product in customer_orders:\n",
+    "        while True:\n",
+    "            entry = input(f\"Enter the price of {product}: \")\n",
+    "            try:\n",
+    "                price = float(entry)\n",
+    "                if price < 0:\n",
+    "                    print(\"Error: Price cannot be negative. Please try again.\")\n",
+    "                else:\n",
+    "                    total_price += price\n",
+    "                    break\n",
+    "            except ValueError:\n",
+    "                print(f\"Error: '{entry}' is not a valid number. Please try again.\")\n",
+    "                \n",
+    "    return total_price"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "id": "c568692b",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Step 3:\n",
+    "def get_customer_orders(inventory):\n",
+    "    # 1. Validate the number of orders\n",
+    "    while True:\n",
+    "        try:\n",
+    "            entry = input(\"How many products do you want to order? \")\n",
+    "            num_orders = int(entry)\n",
+    "            if num_orders < 0:\n",
+    "                print(\"Error: The number of orders cannot be negative.\")\n",
+    "                continue\n",
+    "            break\n",
+    "        except ValueError:\n",
+    "            print(f\"Error: '{entry}' is not a valid number. Please enter an integer.\")\n",
+    "    \n",
+    "    # 2. Collect valid product names\n",
+    "    customer_orders = set()\n",
+    "    \n",
+    "    for i in range(num_orders):\n",
+    "        while True:\n",
+    "            product_name = input(f\"Enter product {i + 1}: \")\n",
+    "            \n",
+    "            # Check if product exists in inventory\n",
+    "            if product_name not in inventory:\n",
+    "                print(f\"Error: '{product_name}' is not in our inventory.\")\n",
+    "                print(f\"Available products: {', '.join(inventory.keys())}\")\n",
+    "                continue\n",
+    "            \n",
+    "            # Check if product has stock available\n",
+    "            if inventory[product_name] <= 0:\n",
+    "                print(f\"Error: '{product_name}' is out of stock.\")\n",
+    "                continue\n",
+    "            \n",
+    "            # Valid product with stock available\n",
+    "            customer_orders.add(product_name)\n",
+    "            break\n",
+    "    \n",
+    "    return customer_orders\n",
+    "\n",
+    "\n",
+    "  \n",
+    "    \n",
+    "\n",
+    "    "
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "id": "5375f1f8",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      "Summary of your order: {'hat', 'book', 'mug'}\n",
+      "\n",
+      "Final Inventory after orders:\n",
+      "  t-shirt: 2\n",
+      "  mug: 2\n",
+      "  hat: 3\n",
+      "  book: 4\n",
+      "  keychain: 1\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "{'book', 'hat', 'mug'}"
+      ]
+     },
+     "execution_count": 9,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "def manage_customer_orders():\n",
+    "    products_list = ['t-shirt', 'mug', 'hat', 'book', 'keychain']\n",
+    "\n",
+    "    inventory = initialize_inventory(products_list)\n",
+    "    customer_orders = get_customer_orders(inventory)\n",
+    "\n",
+    "    print(f\"\\nSummary of your order: {customer_orders}\")  # ✅ fixed f-string\n",
+    "\n",
+    "    for product in customer_orders:  # ✅ iterate set directly, no .items()\n",
+    "        inventory[product] -= 1      # ✅ subtract 1 per product\n",
+    "\n",
+    "    print(\"\\nFinal Inventory after orders:\")\n",
+    "    for product, stock in inventory.items():\n",
+    "        print(f\"  {product}: {stock}\")\n",
+    "    return customer_orders\n",
+    "manage_customer_orders()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "621c5fc9",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Error: Invalid quantity! Please enter a non-negative value.\n",
+      "Error: 'sock' is not in our inventory.\n",
+      "Available products: t-shirt, mug, hat, book, keychain\n",
+      "Error: 'ten' is not in our inventory.\n",
+      "Available products: t-shirt, mug, hat, book, keychain\n",
+      "Error: '10' is not in our inventory.\n",
+      "Available products: t-shirt, mug, hat, book, keychain\n",
+      "Error: '' is not in our inventory.\n",
+      "Available products: t-shirt, mug, hat, book, keychain\n",
+      "Error: '' is not in our inventory.\n",
+      "Available products: t-shirt, mug, hat, book, keychain\n",
+      "Error: '' is not in our inventory.\n",
+      "Available products: t-shirt, mug, hat, book, keychain\n"
+     ]
+    }
+   ],
+   "source": [
+    "def manage_customer_orders():\n",
+    "    products_list = ['t-shirt', 'mug', 'hat', 'book', 'keychain']\n",
+    "\n",
+    "    inventory = initialize_inventory(products_list)\n",
+    "    customer_orders = get_customer_orders(inventory)\n",
+    "\n",
+    "    print(f\"\\nSummary of your order: {customer_orders}\")  # ✅ fixed f-string\n",
+    "\n",
+    "    for product in customer_orders:  # ✅ iterate set directly, no .items()\n",
+    "        inventory[product] -= 1      # ✅ subtract 1 per product\n",
+    "\n",
+    "    print(\"\\nFinal Inventory after orders:\")\n",
+    "    for product, stock in inventory.items():\n",
+    "        print(f\"  {product}: {stock}\")\n",
+    "    return customer_orders\n",
+    "manage_customer_orders()"
+   ]
   }
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3 (ipykernel)",
+   "display_name": "base",
    "language": "python",
    "name": "python3"
   },
@@ -90,7 +290,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.13"
+   "version": "3.13.9"
   }
  },
  "nbformat": 4,