function validate_email(field,alerttxt)
	{
	with (field)
	{
	apos=value.indexOf("@");
	dotpos=value.lastIndexOf(".");
	if (apos<1||dotpos-apos<2) 
	  {alert(alerttxt);return false;}
	else {return true;}
	}
	}

	function validate_form(thisform)
	{
	with (thisform)
	{
	if (validate_email(email,"L'adresse email n'est pas valide")==false)
	  {email.focus();return false}
	}
	}