function startChooseItem(releaseCallback)
  if not releaseCallback then
    error("No mouse release callback parameter set.")
  end
  local mouseGrabberWidget = g_ui.createWidget('UIWidget')
  mouseGrabberWidget:setVisible(false)
  mouseGrabberWidget:setFocusable(false)

  connect(mouseGrabberWidget, { onMouseRelease = releaseCallback })

  mouseGrabberWidget:grabMouse()
  g_mouse.pushCursor('target')
end

function onClickWithMouse(self, mousePosition, mouseButton)
  local item = nil
  if mouseButton == MouseLeftButton then
    local clickedWidget = modules.game_interface.getRootPanel():recursiveGetChildByPos(mousePosition, false)
    if clickedWidget then
      if clickedWidget:getClassName() == 'UIMap' then
        local tile = clickedWidget:getTile(mousePosition)
        if tile then
          if currentSlot == 1 then
             item = tile:getGround()
          else
              local thing = tile:getTopMoveThing()
              if thing and thing:isItem() then
                 item = thing
              else
                 item = tile:getTopCreature()
              end
          end
        elseif clickedWidget:getClassName() == 'UIItem' and not clickedWidget:isVirtual() then
           item = clickedWidget:getItem()
        end
      end
    end
  end
    if item then
       if currentSlot == 4 and not item:isPlayer() then
          modules.game_textmessage.displayFailureMessage('Use it only in players!')
       else
          local player = g_game.getLocalPlayer()               --2  --6 pokedex
          g_game.useInventoryItemWith(player:getInventoryItem(currentSlot):getId(), item)
       end
    end
  g_mouse.popCursor()
  self:ungrabMouse()
  self:destroy()
  mouseclick = false
end