function check_mail_form(LG)
{
	
	form = document.forms['subscription'];
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (form.elements['senderemail'].value == '')				{alert (messages[LG]['email']); return false;}
	if (!filter.test(form.elements['senderemail'].value))		{alert (messages[LG]['invalid_email']); return false;}	
	
	if (form.elements['subject'].value == '')					{alert (messages[LG]['subject_missing']); return false;}
	if (form.elements['message'].value == '')					{alert (messages[LG]['message_missing']); return false;}
	form.elements['act'].value = "send_mail";
	form.submit();

}