function validation(chars,nomChamps,longueur,txt)
{
	var charValid = "abcdefghijklmnopqrstuvwxyz0123456789-_é' àèë " + chars;
	
	if (txt.length < longueur)
	{
		alert(" The  «" + nomChamps + "» field is empty");
		return false;
	}
	
	var s = txt.toLowerCase();
	
	for (var i = 0; i < s.length; i++)
	{
		var car = s.charAt(i);
		
		if (charValid.indexOf(car) < 0)
		{
			alert("This character is ot valid in the «" + nomChamps + "» field :  \"" + car + "\"  ");
			return false;
		}
	}
	
	return true;
}

function validationEmail(nomChamps,email)
{
	if (validation("@.",nomChamps,1,email))
	{
		var arobas = email.indexOf('@');
		
		if ((arobas > 0) && (arobas < (email.length - 4)) && (email.indexOf("..") < 0))
		{
			var domaine = email.substr(arobas + 1);

			if (domaine.indexOf('@') < 0)
			{
				var ipoint = domaine.lastIndexOf('.');
				
				if ((ipoint >= 0) && (ipoint < (domaine.length - 2)))
				{
					return true;
				}
			}
		}
	
		alert("«" + email + "» is not a valid email adress.");
	}

	return false;
}