function setCookie(name, value, expires, path, domain, secure) {
  var curCookie = name + "=" + escape(value) +
      ((expires) ? "; expires=" + expires.toGMTString() : "") +
      ((path) ? "; path=" + path : "") +
      ((domain) ? "; domain=" + domain : "") +
      ((secure) ? "; secure" : "");
  document.cookie = curCookie;
}


function getCookie(name) {
  var dc = document.cookie;
  var prefix = name + "=";
  var begin = dc.indexOf("; " + prefix);
  if (begin == -1) {
    begin = dc.indexOf(prefix);
    if (begin != 0) return null;
  } else
    begin += 2;
  var end = document.cookie.indexOf(";", begin);
  if (end == -1)
    end = dc.length;
  return unescape(dc.substring(begin + prefix.length, end));
}


//barvy pro pozadi hlavni stranky
//puvodni

var barvicky = new Array(
"0C4B8A",
"252573",
"2B2B57",
"45455D",
"5C5C5E",
"822A2A",
"613636",
"615353",
"15450E",
"404C3E",
"604925",
"62420D"
);

/*
var barvicky = new Array(
"003366",
"07073D",
"131332",
"2E2E49",
"48484F",
"5B1111",
"361A1A",
"423636",
"092A04",
"2B3729",
"3F2E13",
"3F2700"
);
*/

/*
var barvicky = new Array(
"25588A",
"4B4B6C",
"52526C",
"64646C",
"6B6B6B",
"973C3C",
"6B3C3C",
"625050",
"285D20",
"4B5D49",
"684E24",
"634618"
);
*/


//nastavi cookie s nejakou barvou pozadi a vrati ji
function set_random_bg_color(){
	var c = barvicky[Math.round((Math.random() * 100) % barvicky.length)];
	setCookie("bg_color", c);	
	//alert(c);
	return c;
}


/*
	zjisti ulozenou barvu pozadi, pokud zadna neni, tak ji ulozi
*/
function get_bg_color(){
	//alert('sem tu');
	var col = getCookie("bg_color");	
	if(col == null || col == "" || col == 'undefined'){ //barva jeste neni nastavena, nastav ji
		col = set_random_bg_color();
	}
	return col;
}