$(document).ready(function(){

   var bg = new Array('header.jpg', 'header1.jpg', 'header2.jpg', 'header3.jpg', 'header4.jpg');
   var cursor = 2;
   var niv = 1;
   setInterval(changeHeader, 4000);
     function changeHeader(){

        if(cursor>=(bg.length-1)) cursor = 0;
        if(cursor<0) cursor = 0;
        if(niv==1)var nextniv=2;else nextniv=1;

        $("#headercache" + nextniv).css({"display" : "block"});

        $("#headercache" + niv).fadeOut('slow',function() {
            $("#headercache" + (nextniv)).css("z-index",'1');
            $("#headercache" + (niv)).css("z-index",'0');
            $("#headercache" + (niv)).css("background","transparent url(/images/"+bg[cursor]+") repeat-x 0 0");
            if(niv == 1) niv=2; else niv=1;
            cursor++;
        });

    }
});