/**
 * Calculate Age
 * 
 * Calculates the amount of time since the date specified with yr, mon, and day.
 * The parameter "countunit" can be "years", "months", or "days" and is the duration 
 * between the specified day and today in the selected denomination. The "decimals" 
 * parameter allows you to set a decimal place to round to for days and months return 
 * values. Rounding is also meant for days and months and can be "roundup" or "rounddown" 
 * based solely on the properties of Math.ceil and math.floor respectively.
 * Sample - displayage(1997, 11, 24, "years", 0, "rounddown")
 */
function displayage( yr, mon, day, countunit, decimals, rounding ) {
 
	// Starter Variables
	today = new Date();
	yr = parseInt(yr);
	mon = parseInt(mon);
	day = parseInt(day);
	var one_day = 1000*60*60*24;
	var one_month = 1000*60*60*24*30;
	var one_year = 1000*60*60*24*30*12;
	var pastdate = new Date(yr, mon-1, day);
	var return_value = 0;
 
	finalunit = ( countunit == "days" ) ? one_day : ( countunit == "months" ) ? one_month : one_year;
	decimals = ( decimals <= 0 ) ? 1 : decimals * 10;
 
	if ( countunit != "years" ) {
		if ( rounding == "rounddown" )
			return_value = Math.floor ( ( today.getTime() - pastdate.getTime() ) / ( finalunit ) * decimals ) / decimals;
		else
			return_value = Math.ceil ( ( today.getTime() - pastdate.getTime() ) / ( finalunit ) * decimals ) / decimals;
	} else {
		yearspast = today.getFullYear()-yr-1;
		tail = ( today.getMonth() > mon - 1 || today.getMonth() == mon - 1 && today.getDate() >= day ) ? 1 : 0;
		return_value = yearspast + tail;
	}
 
	return return_value;
 
}
//javascript/2116