function isDateString(sDate)
{	var iaMonthDays = [31,28,31,30,31,30,31,31,30,31,30,31]
	var iaDate = new Array(3)
	var year, month, day

	if (arguments.length != 1) return false
	iaDate = sDate.toString().split("-")
	if (iaDate.length != 3) return false
	if (iaDate[1].length > 2 || iaDate[2].length > 2) return false
	if (isNaN(iaDate[0])||isNaN(iaDate[1])||isNaN(iaDate[2])) return false

	year = parseFloat(iaDate[0])
	month = parseFloat(iaDate[1])
	day=parseFloat(iaDate[2])

	if (year < 1900 || year > 2100) return false
	if (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0)) iaMonthDays[1]=29;
	if (month < 1 || month > 12) return false
	if (day < 1 || day > iaMonthDays[month - 1]) return false
	return true
}

function stringToDate(sDate, bIgnore)
{	var bValidDate, year, month, day
	var iaDate = new Array(3)
	
	if (bIgnore) bValidDate = true
	else bValidDate = isDateString(sDate)
	
	if (bValidDate)
	{  iaDate = sDate.toString().split("-")
		year = parseFloat(iaDate[0])
		month = parseFloat(iaDate[1]) - 1
		day=parseFloat(iaDate[2])
		return (new Date(year,month,day))
	}
	else return (new Date(1900,1,1))
}

function Datediff(sDate, bIgnore)
{	var bValidDate, year, month, day
	var iaDate = new Array(3)
	
	if (bIgnore) bValidDate = true
	else bValidDate = isDateString(sDate)
	
	if (bValidDate)
	{  iaDate = sDate.toString().split("-")
		year = parseFloat(iaDate[0])
		month = parseFloat(iaDate[1]) - 1
		day=parseFloat(iaDate[2])
		if (month+1>=13)
		{
			year++
		}
		else
		{
			month++
		
		}
		return (new Date(year,month,day))
	}
	else return (new Date(1900,1,1))
}