var restricted_calendar = false;
var forward_period = false;

// Milliseconds per two months (60 days)
var days = 0;
var ms_per_day = ( 24 * 60 * 60 * 1000 );

function show_calendar(str_target, str_datetime) {
	var period = ms_per_day * days;
	var arr_months = ["Януари", "Февруари", "Март", "Април", "Май", "Юни",
		"Юли", "Август", "Септември", "Октомври", "Ноември", "Декември"];
	var week_days = ["Не", "По", "Вт", "Ср", "Че", "Пе", "С "];
	var n_weekstart = 1; // day week starts from (normally 0 or 1)

	var dt_datetime = (str_datetime == null || str_datetime =="" ?  new Date() : str2dt(str_datetime));
	var dt_prev_month = new Date(dt_datetime);
	dt_prev_month.setMonth(dt_datetime.getMonth()-1);
	var dt_next_month = new Date(dt_datetime);
	dt_next_month.setMonth(dt_datetime.getMonth()+1);
	var dt_firstday = new Date(dt_datetime);
	dt_firstday.setDate(1);
	dt_firstday.setDate(1-(7+dt_firstday.getDay()-n_weekstart)%7);
	var dt_lastday = new Date(dt_next_month);
	dt_lastday.setDate(0);
	var ms = new Date();

	// html generation (feel free to tune it for your particular application)
	// print calendar header
	var str_buffer = new String (
		"<html>\n"+
		"<head>\n"+
		"	<title>Изберете дата</title>\n"+
		"	<meta http-equiv=\"Content-Type\" content=\"text/html; charset=windows-1251\">"+
		"</head>\n"+
		"<body bgcolor=\"White\">\n"+
		"<table class=\"clsOTable\" cellspacing=\"0\" border=\"0\" width=\"100%\">\n"+
		"<tr><td bgcolor=\"#4682B4\">\n"+
		"<table cellspacing=\"1\" cellpadding=\"3\" border=\"0\" width=\"100%\">\n"+
		"<tr>\n	<td bgcolor=\"#4682B4\"><a href=\"javascript:window.opener.show_calendar('"+
//		str_target+"', '"+ dt2dtstr(dt_prev_month)+"'+document.cal.time.value);\">"+
		str_target+"', '"+ dt2dtstr(dt_prev_month)+"');\">"+
		"<img src=\"images/prev.gif\" width=\"16\" height=\"16\" border=\"0\""+
		" alt=\"предишен месец\"></a></td>\n"+
		"	<td bgcolor=\"#4682B4\" colspan=\"5\">"+
		"<font color=\"white\" face=\"tahoma, verdana\" size=\"2\">"
		+arr_months[dt_datetime.getMonth()]+" "+dt_datetime.getFullYear()+"</font></td>\n"+
		"	<td bgcolor=\"#4682B4\" align=\"right\"><a href=\"javascript:window.opener.show_calendar('"
//		+str_target+"', '"+dt2dtstr(dt_next_month)+"'+document.cal.time.value);\">"+
		+str_target+"', '"+dt2dtstr(dt_next_month)+"');\">"+
		"<img src=\"images/next.gif\" width=\"16\" height=\"16\" border=\"0\""+
		" alt=\"следващ месец\"></a></td>\n</tr>\n"
	);

	var dt_current_day = new Date(dt_firstday);
	// print weekdays titles
	str_buffer += "<tr>\n";
	for (var n=0; n<7; n++)
		str_buffer += "	<td bgcolor=\"#87CEFA\">"+
		"<font color=\"white\" face=\"tahoma, verdana\" size=\"2\">"+
		week_days[(n_weekstart+n)%7]+"</font></td>\n";
	// print calendar table
	str_buffer += "</tr>\n";
	while (dt_current_day.getMonth() == dt_datetime.getMonth() ||
		dt_current_day.getMonth() == dt_firstday.getMonth()) {
		// print row heder
		str_buffer += "<tr>\n";
		for (var n_current_wday=0; n_current_wday<7; n_current_wday++) {
				if (dt_current_day.getDate() == dt_datetime.getDate() &&
					dt_current_day.getMonth() == dt_datetime.getMonth())
					// print current date
					str_buffer += "	<td bgcolor=\"#FFB6C1\" align=\"right\">";
				else if (dt_current_day.getTime() < ms.getTime()-period && restricted_calendar)
					str_buffer += " <td bgcolor=\"#FFFFFF\" align=\"right\">";
				else if (dt_current_day.getDay() == 0 || dt_current_day.getDay() == 6)
					// weekend days
					str_buffer += "	<td bgcolor=\"#DBEAF5\" align=\"right\">";
				else
					// print working days of current month
					str_buffer += "	<td bgcolor=\"white\" align=\"right\">";

				if (dt_current_day.getTime() < ms.getTime()-period && restricted_calendar)
					str_buffer += "<font color=\"#000080\" face=\"tahoma, verdana\" size=\"2\">";
				else if (dt_current_day.getTime() > ms.getTime() && forward_period == false)
					str_buffer += "<font color=\"#000080\" face=\"tahoma, verdana\" size=\"2\">";
				else if (dt_current_day.getMonth() == dt_datetime.getMonth())
					// print days of current month
					str_buffer += "<a href=\"javascript: window.opener.document."+str_target+
					".value='"+dt2dtstr(dt_current_day)+"'; window.close();\">"+
//					".value='"+dt2dtstr(dt_current_day)+"'+document.cal.time.value; window.close();\">"+
					"<font color=\"black\" face=\"tahoma, verdana\" size=\"2\">";
				else
					// print days of other months
					str_buffer += "<a href=\"javascript: window.opener.document."+str_target+
					".value='"+dt2dtstr(dt_current_day)+"'; window.close();\">"+
//					".value='"+dt2dtstr(dt_current_day)+"'+document.cal.time.value; window.close();\">"+
					"<font color=\"gray\" face=\"tahoma, verdana\" size=\"2\">";
				str_buffer += dt_current_day.getDate()+"</font></a></td>\n";
				dt_current_day.setDate(dt_current_day.getDate()+1);
		}
		// print row footer
		str_buffer += "</tr>\n";
	}
	// print calendar footer
	str_buffer +=
		"<form name=\"cal\" method=\"post\" onSubmit=\"javascript: return false;\" action=\"#\">\n<tr><td colspan=\"7\" bgcolor=\"#87CEFA\">"+
//		"<font color=\"White\" face=\"tahoma, verdana\" size=\"2\">"+
//		"Час: <input type=\"text\" name=\"time\" value=\""+dt2tmstr(dt_datetime)+
//		"\" size=\"8\" maxlength=\"8\"></font></td></tr>\n" +
		"</form>\n</table>\n" +
		"</tr>\n</td>\n</table>\n" +
		"</body>\n" +
		"</html>\n";

	var vWinCal = window.open("", "Calendar", 
		"width=200,height=220,status=yes,resizable=yes,top=200,left=200");
	vWinCal.opener = self;
	var calc_doc = vWinCal.document;
	calc_doc.write (str_buffer);
	calc_doc.close();
}
// datetime parsing and formatting routimes. modify them if you wish other datetime format
function str2dt (str_datetime) {
//	var re_date = /^(\d+)\/(\d+)\/(\d+)\s+(\d+)\:(\d+)\:(\d+)$/;
	var re_date = /^(\d+)\/(\d+)\/(\d+)\s?$/;
	if (!re_date.exec(str_datetime))
		return alert("Invalid Datetime format: "+ str_datetime);
	return (new Date (RegExp.$3, RegExp.$2-1, RegExp.$1, RegExp.$4, RegExp.$5, RegExp.$6));
}
function dt2dtstr (dt_datetime) {
    day1 = new String (dt_datetime.getDate());
    mounth1 = new String ((dt_datetime.getMonth()+1));
    if (day1.length == 1) { day1 = '0'+ day1;};
    if (mounth1.length == 1) { mounth1 = '0'+ mounth1;};
    datetime = new String ( day1+"/"+mounth1+"/"+dt_datetime.getFullYear());
    
	return (datetime);
}
function dt2tmstr (dt_datetime) {
    Hours1 = new String (dt_datetime.getHours());
    Minutes1 = new String (dt_datetime.getMinutes());
    Seconds1 = new String (dt_datetime.getSeconds());
    if (Hours1.length == 1) { Hours1 = '0'+ Hours1;};
    if (Minutes1.length == 1) { Minutes1 = '0'+ Minutes1;};
    if (Seconds1.length == 1) { Seconds1 = '0'+ Seconds1;};
    time1 = new String (Hours1+":"+Minutes1+":"+Seconds1);
	return (time1);
}

