function checkIsValidForm(txt1, txt2){
	var email = document.getElementById('form_data_mail').value;
	var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	var groups = document.getElementsByName('tipas[]');
	var isValid = false;

	for(var i=0; i<groups.length; i++){
		if(groups[i].checked) isValid = true;
	}

	if(filter.test(email) && isValid){
		return true;
	}
	else{
		if(!filter.test(email)) alert(txt1);
		else if(!isValid) alert(txt2);
		return false;
	}
}
function checkIsValidForm2(txt){
	var email = document.getElementById('form_data_mail2').value;
	var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;

	if(filter.test(email)){
		return true;
	}
	else{
		alert(txt);
		return false;
	}
}