function calendar(date) {
// If no parameter is passed use the current date.
if(date == null)
date = new Date();

day = date.getDate();
month = date.getMonth();
year = date.getFullYear();

months = new Array('January','February','March','April','May','June','July','August','September','October','November','December');

this_month = new Date(year, month, 1);
next_month = new Date(year, month + 1, 1);

// Find out when this month starts and ends.
first_week_day = this_month.getDay();
days_in_this_month = Math.round((next_month.getTime() - this_month.getTime()) / (1000 * 60 * 60 * 24));

calendar_html = '<table style="background-color:005797; color:ffffff;">';
calendar_html += '<tr><td colspan="7" style="background-color:005797; color:ffffff; text-align: center;">' + months[month] + ' ' + year + '</td></tr>';
calendar_html += '<tr>';

// Fill the first week of the month with the appropriate number of blanks.
for(week_day = 0; week_day < first_week_day; week_day++) {
calendar_html += '<td style="background-color:ffffff; color:006AD5;"> </td>';
}

week_day = first_week_day;
for(day_counter = 1; day_counter <= days_in_this_month; day_counter++) {
week_day %= 7;
if(week_day == 0)
calendar_html += '</tr><tr>';

// Do something different for the current day.
if(day == day_counter)
calendar_html += '<td style="text-align: center;"><b>' + day_counter + '</b></td>';
else
calendar_html += '<td style="background-color:ffffff; color:006AD5; text-align: center;"> ' + day_counter + ' </td>';

week_day++;
}

calendar_html += '</tr>';
calendar_html += '</table>';

// Display the calendar.
document.write(calendar_html);
}