function checkDate(input, champ){
	var validformat=/^\d{4}\-\d{2}\-\d{2}$/ //Basic check for format validity
	var returnval=false
			
	if (!validformat.test(input.value))
		alert("Le format de la " + champ + " est incorrect.")
	else{ //Detailed check for valid date ranges
		var yearfield=input.value.split("-")[0]
		var monthfield=input.value.split("-")[1]
		var dayfield=input.value.split("-")[2]
		var dayobj = new Date(yearfield, monthfield-1, dayfield)

		if ((dayobj.getMonth()+1!=monthfield)||(dayobj.getDate()!=dayfield)||(dayobj.getFullYear()!=yearfield))
			alert("Jour, mois ou année de la " + champ + " invalide.")
		else
			returnval=true
	}

	if (returnval==false) input.select()
	
	return returnval
}

function convertDateToString(date)
{
	var str;
	var tab;
	var jour;
	var mois;
	var annee;
	
	if(date == null)
	{
		str = "";
	}
	else
	{
		str = date.getDate()+"-"+(date.getMonth()+1)+"-"+date.getFullYear();
		
		tab = str.split('-');
		jour = tab[0];
		mois = tab[1];
		annee = tab[2];
		
		if(jour.length == 1)	jour = "0" + jour;
		if(mois.length == 1)	mois = "0" + mois;
		
		str = annee + "-" + mois + "-" + jour;
	}
	
	return str;
}