function isTime(timeStr) {
// Checks if time is in HH:MM AM/PM format.

var timePat = /^(\d{2}):(\d{2})(AM|am|PM|pm)$/;

var matchArray = timeStr.match(timePat);
if (matchArray == null) {
	return false;
}
hour = matchArray[1];
minute = matchArray[2];
ampm = matchArray[3];

second = null;
if (ampm=="" || hour=="" || minute=="" ) { 
	return false;
}
if (hour < 0  || hour > 12) {
	return false;
}
if (minute<0 || minute > 59) {
	return false;
}
return true;
}

function isMilTime(timeStr) {
// Checks if time is in HH:MM military format.

var timePat = /^(\d{2}):(\d{2})$/;

var matchArray = timeStr.match(timePat);
if (matchArray == null) {
	return false;
}
hour = matchArray[1];
minute = matchArray[2];

second = null;
if ( hour=="" || minute=="" ) { 
	return false;
}
if (hour < 0  || hour > 23) {
	return false;
}
if (minute<0 || minute > 59) {
	return false;
}
return true;
}