diff --git a/attributes.json b/attributes.json
index 85dc730..944a30b 100644
--- a/attributes.json
+++ b/attributes.json
@@ -1,6 +1,10 @@
 {
     "dough": ["thick"],
-    "drink": ["pepsi", "cola", "water"],
+    "drink": {
+        "pepsi": {"price" : 10},
+        "cola": {"price" : 10},
+        "water": {"price" : 5}
+    },
     "food": ["pizza"],
     "meat": ["chicken", "ham", "tuna"],
     "sauce": ["garlic", "1000w"],
diff --git a/src/service/dialog_state_monitor.py b/src/service/dialog_state_monitor.py
index 67b15b5..73705e8 100644
--- a/src/service/dialog_state_monitor.py
+++ b/src/service/dialog_state_monitor.py
@@ -44,7 +44,10 @@ class DialogStateMonitor:
                 stage['completed'] = True
                 return
 
-    def pizza_exists(self, name: str) -> bool:
+    def item_exists(self, type: str, name: str) -> bool:
+        return normalize(name) in self.state['constants'][type]
+
+    def drink_exists(self, name: str) -> bool:
         return normalize(name) in self.state['constants']['pizza']
 
     def get_total_cost(self) -> int:
@@ -58,12 +61,12 @@ class DialogStateMonitor:
             new_order = dict()
             for slot in frame.slots:
                 value = normalize(slot.value)
-                if slot.name == 'pizza':
-                    if self.pizza_exists(value) is False:
+                if slot.name == 'pizza' or slot.name == 'drink':
+                    if self.item_exists(slot.name, value) is False:
                         self.state['was_previous_order_invalid'] = True
                         return
                     self.state['was_previous_order_invalid'] = False
-                    self.state['total_cost'] += self.state['constants']['pizza'][value]['price']
+                    self.state['total_cost'] += self.state['constants'][slot.name][value]['price']
                 new_order[slot.name] = value
             self.state['belief_state']['order'].append(new_order)
         elif frame.act == 'inform/address':
diff --git a/src/test/dialog_state_monitor.py b/src/test/dialog_state_monitor.py
index ae4b44a..5d8087b 100644
--- a/src/test/dialog_state_monitor.py
+++ b/src/test/dialog_state_monitor.py
@@ -4,8 +4,9 @@ from src.model.slot import Slot
 
 dsm = DialogStateMonitor()
 
-assert dsm.pizza_exists('capri') is True
-assert dsm.pizza_exists('buraczana') is False
+assert dsm.item_exists('pizza', 'capri') is True
+assert dsm.item_exists('pizza', 'buraczana') is False
+assert dsm.item_exists('drink', 'cola') is True
 assert dsm.state['was_previous_order_invalid'] is False
 
 frame1 = Frame('user', 'inform/order', [Slot('pizza', 'margarita'), Slot('sauce', 'ketchup')])
@@ -16,6 +17,9 @@ dsm.update(frame2)
 assert dsm.get_total_cost() == 60
 frame3 = Frame('user', 'inform/order-complete', [])
 dsm.update(frame3)
+frame4 = Frame('user', 'inform/order', [Slot('drink', 'cola')])
+dsm.update(frame4)
+assert dsm.get_total_cost() == 70
 
 assert dsm.state['belief_state']['order'][0]['pizza'] == 'margarita'
 assert dsm.state['belief_state']['order'][0]['sauce'] == 'ketchup'
@@ -23,7 +27,7 @@ assert dsm.state['belief_state']['order-complete'] is True
 assert dsm.state['history'][0] == frame1
 assert dsm.state['history'][1] == frame2
 assert dsm.state['history'][2] == frame3
-
+assert dsm.state['history'][3] == frame4
 
 assert dsm.get_current_active_stage() == 'collect_food'
 dsm.mark_current_stage_completed()