function dateCheck(myDay, myMonth, myYear)
{
	
	var flag = true
	if (myMonth.value != "" || myDay.value != "" || myYear.value != "")
	{
		fullYear = myYear.value;
		fullMonth = myMonth.value;

		if (fullMonth > 12 || fullMonth < 1)
		{
			alert("Le mois de votre date n'est pas valide");			
			flag = false;
		}
		
		if (fullYear.length != 4)
		{
			alert("L'année de votre date doit contenir quatres chiffres");
			flag = false;
		}

		timeA = new Date(fullYear, fullMonth,1);
		timeDifference = timeA - 86400000;
		timeB = new Date(timeDifference);

		var daysInMonth = timeB.getDate();
		if (myDay.value > daysInMonth)
		{
			alert("Veuillez introduire une date valide\n\nLe format doit être 'JJ/MM/AAAA'");
			flag = false;
		}
        }
        else
        	flag=false
	return flag;
}