Tygrik = function()
{
}

Tygrik.MarkerStart = "Start";
Tygrik.MarkerStop = "Stop";
Tygrik.MarkerList = "List";
Tygrik.MarkerItem = "Item";
Tygrik.MarkerOdkaz = "Odkaz";
Tygrik.MarkerVyraz = "Vyraz";

Date.prototype.AddMonths = function(iAddMonths)
{
    var iDay = this.getDate();
    var iMonth = this.getMonth()+1;
    var iYear = this.getFullYear();
    iMonth = iMonth + iAddMonths;
    while (iMonth > 12)
    {
       iYear += 1;
       iMonth -= 12;     
    }
    while (iMonth < 0)
    {
       iYear -= 1;
       iMonth += 12;     
    }
    var dtReturn = new Date(this);
    dtReturn.setFullYear(iYear);
    dtReturn.setMonth(iMonth-1);
    return dtReturn;
}