$(document).ready(function()
{
       //slides the element with class "menu_body" when paragraph with class "menu_head" is clicked 
       $("#firstpane p.menu_head").click(function()
    {
              $(this).css({backgroundImage:"url(./css/img/strzalka.gif)"}).next("div.menu_body").slideToggle(500).siblings("div.menu_body").slideUp("slow");
              $(this).siblings().css({backgroundImage:"url(./css/img/strzalka.gif)"});
       });
       //slides the element with class "menu_body" when mouse is over the paragraph
       $("#secondpane p.menu_head").mouseover(function()
    {
            $(this).css({backgroundImage:"url(./css/img/strzalka.gif)"}).next("div.menu_body").slideDown(500).siblings("div.menu_body").slideUp("slow");
         $(this).siblings().css({backgroundImage:"url(./images/manu.gif)"});
       });
});