var objTxtBoxTarget
var objLTDDate
function show_calendar(str_target, str_datetime, divId2write) {

    objTxtBoxTarget = document.getElementById(str_target);

    var arr_months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
    var week_days = ["S", "M", "T", "W", "T", "F", "S"];
    var n_weekstart = 0; // 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);

    // html generation (feel free to tune it for your particular application)
    // print calendar header
    var str_buffer = new String(
		"<table cellspacing=\"0\" border=\"0\" width=\"100%\" >\n" +
		"<tr><td bgcolor=\"#353535\">\n" +
		"<table cellspacing=\"0\" cellpadding=\"3\" border=\"0\" width=\"100%\">\n" +
		"<tr>\n	<td><a href=\"javascript:show_calendar('" +
		str_target + "', '" + dt2dtstr(dt_prev_month) + "'+document.getElementById('time').value,'" + divId2write + "');\">" +
		"<img src=\"" + _storageImagesURL + "double_arrow_left.gif\"  border=\"0\"" +
		" alt=\"previous month\"></a></td>\n" +
		"	<td style=\"text-align:center;color:White;font-family:Arial; font-size:12px;\" colspan=\"5\">" + arr_months[dt_datetime.getMonth()] + " " + dt_datetime.getFullYear() + "</font></td>\n" +
		"	<td align=\"right\"><a href=\"javascript:show_calendar('"
		+ str_target + "', '" + dt2dtstr(dt_next_month) + "'+document.getElementById('time').value,'" + divId2write + "');\">" +
		"<img src=\"" + _storageImagesURL + "double_arrow_right.gif\"  border=\"0\"" +
		" alt=\"next month\"></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  style=\"background-color:#CDCC34;color:Black; font-family:Arial; font-size:11px;\" align=\"center\">" +
		week_days[(n_weekstart + n) % 7] + "</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 style=\"text-align:center;border:solid 1px #CDCC34;\" >";
            else if (dt_current_day.getDay() == 6)
            // weekend days
                str_buffer += "	<td style=\"text-align:center;\">";
            else
            // print working days of current month
                str_buffer += "	<td style=\"text-align:center;\">";

            if (dt_current_day.getMonth() == dt_datetime.getMonth())
            // print days of current month
                str_buffer += "<a href=\"javascript:void(0);\" onclick=\"objTxtBoxTarget.value='" + dt2dtstr(dt_current_day) + "'+document.getElementById('time').value;changeCurrentDate(this); \" style=\"color:#CCCD34;font-size:12px;text-decoration:underline;\">" +
					"";
            else
            // print days of other months
                str_buffer += "<a href=\"javascript:void(0);\" onclick=\"objTxtBoxTarget.value='" + dt2dtstr(dt_current_day) + "'+document.getElementById('time').value; \" style=\"text-align:center;color:gray;font-size:12px;text-decoration:line-through;\">";
            str_buffer += dt_current_day.getDate() + "</a></td>\n";
            dt_current_day.setDate(dt_current_day.getDate() + 1);
        }
        // print row footer
        str_buffer += "</tr>\n";
    }
    // print calendar footer
    str_buffer +=
		"</table></td></tr></table>" +
		"<input type=\"hidden\" id=\"time\" name=\"time\" value=\"" + dt2tmstr(dt_datetime) + "\" \>";
    var calObj = document.getElementById(divId2write);
    calObj.innerHTML = str_buffer;
    objTxtBoxTarget.value = dt2dtstr(new Date());
}
// datetime parsing and formatting routimes. modify them if you wish other datetime format
function str2dt(str_datetime) {
    var re_date = /^(\d+)\/(\d+)\/(\d+)$/;
    if (!re_date.exec(str_datetime)) {
        return alert("Invalid Datetime format: " + str_datetime);
    }
    return (new Date(RegExp.$3, RegExp.$2 - 1, RegExp.$1));
}
function dt2dtstr(dt_datetime) {
    return (new String(dt_datetime.getDate() + "/" + (dt_datetime.getMonth() + 1) + "/" + dt_datetime.getFullYear()));
}
function dt2tmstr(dt_datetime) {
    return ""
}
function changeCurrentDate(objTD) {
    if (objLTDDate) {
        objLTDDate.style.color = '#CDCC34';
        objLTDDate.style.backgroundColor = 'Transparent';
    }
    objTD.style.color = 'black';
    objTD.style.backgroundColor = '#CDCC34';
    objLTDDate = objTD;
}