diff --git a/billard/templatetags/display_client.py b/billard/templatetags/display_client.py
index f4a0c91..d5158aa 100644
--- a/billard/templatetags/display_client.py
+++ b/billard/templatetags/display_client.py
@@ -18,6 +18,7 @@ def display_client(client, desk_no):
     if not desk.enabled:
         return ''
     acc = desk.accounting_set.all()[:3][::-1]
+    _calc_prize(desk, acc)
     html = '<div class="col col-12 col-lg-6">\n'
     html += '    <div class="table-info alert {}">\n'.format(_get_alert_name(desk))
     html += '        <h4 style="text-align: center">({}) {}</h4>\n'.format(desk_no, desk.name)
@@ -57,6 +58,16 @@ def _get_alert_name(desk):
         a = acc[-1]
         if a.time_to is None:
             alert = 'alert-info'
+    before5min = datetime.now() - timedelta(minutes=5)
+    if desk.client.last_seen is not None and desk.client.last_seen < before5min:
+        alert = 'alert-danger'
+    return alert
+
+
+def _calc_prize(desk, acc):
+    if acc is not None and len(acc) > 0:
+        a = acc[-1]
+        if a.time_to is None:
             prize, u1, u2 = utils.get_prize_for(
                 start=a.time_from,
                 end=datetime.now(),
@@ -68,7 +79,3 @@ def _get_alert_name(desk):
             prize = '{0:.2f}'.format(prize)
             if prize != a.prize:
                 a.prize = prize
-    before5min = datetime.now() - timedelta(minutes=5)
-    if desk.client.last_seen is not None and desk.client.last_seen < before5min:
-        alert = 'alert-danger'
-    return alert