diff --git a/application/mainwindow.cpp b/application/mainwindow.cpp
index fdd86ba..e7327da 100644
--- a/application/mainwindow.cpp
+++ b/application/mainwindow.cpp
@@ -178,3 +178,13 @@ void MainWindow::on_actionCountry_register_triggered()
     }
 
 }
+
+void MainWindow::on_actionAbout_Qt_triggered()
+{
+    QMessageBox::aboutQt(this);
+}
+
+void MainWindow::on_actionAbout_triggered()
+{
+    QMessageBox::about(this, tr("About prodejna"), tr("Modular cash register software under GPL license.\n(C) 2015 - 2017 Josef Rokos, Zdenek Jonák"));
+}
diff --git a/application/mainwindow.h b/application/mainwindow.h
index 543e84d..717f073 100644
--- a/application/mainwindow.h
+++ b/application/mainwindow.h
@@ -39,6 +39,10 @@ private slots:
 
     void on_actionCountry_register_triggered();
 
+    void on_actionAbout_Qt_triggered();
+
+    void on_actionAbout_triggered();
+
 private:
     Ui::MainWindow *ui;
     LoginDialog *m_loginDialog;
diff --git a/application/mainwindow.ui b/application/mainwindow.ui
index ce35d2f..886c2be 100644
--- a/application/mainwindow.ui
+++ b/application/mainwindow.ui
@@ -60,7 +60,7 @@
      <x>0</x>
      <y>0</y>
      <width>1000</width>
-     <height>20</height>
+     <height>25</height>
     </rect>
    </property>
    <widget class="QMenu" name="menuFile">
@@ -79,8 +79,16 @@
     <addaction name="actionPost_register"/>
     <addaction name="actionCountry_register"/>
    </widget>
+   <widget class="QMenu" name="menuHelp">
+    <property name="title">
+     <string>Help</string>
+    </property>
+    <addaction name="actionAbout"/>
+    <addaction name="actionAbout_Qt"/>
+   </widget>
    <addaction name="menuFile"/>
    <addaction name="menuRegisters"/>
+   <addaction name="menuHelp"/>
   </widget>
   <widget class="QToolBar" name="mainToolBar">
    <attribute name="toolBarArea">
@@ -126,12 +134,22 @@
   </action>
   <action name="actionPost_register">
    <property name="text">
-    <string>Post register</string>
+    <string>&amp;Post register</string>
    </property>
   </action>
   <action name="actionCountry_register">
    <property name="text">
-    <string>Country register</string>
+    <string>&amp;Country register</string>
+   </property>
+  </action>
+  <action name="actionAbout">
+   <property name="text">
+    <string>About</string>
+   </property>
+  </action>
+  <action name="actionAbout_Qt">
+   <property name="text">
+    <string>About Qt</string>
    </property>
   </action>
  </widget>
diff --git a/camp/campform.ui b/camp/campform.ui
index 359af06..6a03d53 100644
--- a/camp/campform.ui
+++ b/camp/campform.ui
@@ -1,21 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
- <author/>
- <comment/>
- <exportmacro/>
  <class>CampForm</class>
  <widget class="QWidget" name="CampForm">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>400</width>
-    <height>300</height>
+    <width>462</width>
+    <height>403</height>
    </rect>
   </property>
   <property name="windowTitle">
    <string>Form</string>
   </property>
  </widget>
- <pixmapfunction/>
+ <resources/>
  <connections/>
 </ui>
diff --git a/camp/settings/campsettingsform.cpp b/camp/settings/campsettingsform.cpp
index c4e43af..7cdd305 100644
--- a/camp/settings/campsettingsform.cpp
+++ b/camp/settings/campsettingsform.cpp
@@ -4,6 +4,7 @@
 
 #include <settingsservice.h>
 #include <QScroller>
+#include <QMessageBox>
 
 CampSettingsForm::CampSettingsForm(QWidget *parent) :
     FormBinder<CampSettings>(parent),
@@ -58,13 +59,47 @@ bool CampSettingsForm::saveRecord()
 
     Service<PersonPrice> personSrv;
     Service<Sale> saleSrv;
+    bool ret = true;
+
+    connect(&personSrv, &IService::dbErrorDelete, [&ret, this](QString){
+        QMessageBox::critical(this, tr("Cannot delete"), tr("Price already used"));
+        ret = false;
+    });
 
     foreach (PersonPricePtr p, personSrv.all()) {
-        personSrv.erase(p);
+        bool found = false;
+        foreach (PersonPricePtr price, m_personPriceModel->list()) {
+            if (price->id() == p->id())
+            {
+                found = true;
+                break;
+            }
+        }
+
+        if (!found)
+        {
+            personSrv.erase(p);
+        }
     }
 
     foreach (PersonPricePtr p, m_personPriceModel->list()) {
-        personSrv.save(p);
+        bool found = false;
+        foreach (PersonPricePtr price, personSrv.all()) {
+            if (price->id() == p->id())
+            {
+                found = true;
+                break;
+            }
+        }
+
+        if (!found)
+        {
+            personSrv.save(p);
+        }
+        else
+        {
+            personSrv.update(p);
+        }
     }
 
     foreach (SalePtr s, saleSrv.all()) {
@@ -75,7 +110,7 @@ bool CampSettingsForm::saveRecord()
         saleSrv.save(s);
     }
 
-    return true;
+    return ret;
 }
 
 void CampSettingsForm::loadEntity()
diff --git a/core/gridform.h b/core/gridform.h
index 1823f25..2f833d4 100644
--- a/core/gridform.h
+++ b/core/gridform.h
@@ -173,7 +173,7 @@ private slots:
 
     // IGridForm interface
 protected:
-    void handleNewRecord() override
+    virtual void handleNewRecord() override
     {
         if (m_form == NULL)
         {
@@ -186,7 +186,7 @@ protected:
         m_formHandler->showForm(m_form);
     }
 
-    void handleEditRecord() override
+    virtual void handleEditRecord() override
     {
         if (m_form == NULL || m_tableModel == NULL || tableView()->currentIndex().row() < 0)
         {