//Verifie si un champ est rempli
function present(element) 
{
	var id_div = "verif_"+element.id;
	
	if(element.value=="")
	{
		writediv('This field is obligatory', id_div);
		$(id_div).style.display = "block";
		return false;
	}
	else 
	{
		$(id_div).style.display = "none";
		return true;
	}
}

//Cette fonction verifie que le mail contient un @ et un point 
function verif_email(element)
{
	var div_id = "verif_"+element.id;
	
	var res = element.value.indexOf("@");
	var res2 = element.value.indexOf(".");
	
	var domaine = element.value.substr(res+1);
	
	if(element.value=="")
	{
		writediv('This field is obligatory', div_id);
		$(div_id).style.display = "block";
		return false;
	}
	else
	{
		if ((res==-1 || res2==-1) && element.value!="") 
		{
			writediv('Your E-Mail address is not correct', div_id)
			$(div_id).style.display = "block";	
			return false;		
		} 
		else
		{
			$(div_id).style.display = "none";
			return true;
		}
	}
}