function ZobrazSkryjPole(_name)
{
	pole = document.getElementById(_name);
	//popisek = pole.previousSibling;
	
	if(pole.style.visibility == 'visible')
	{
		pole.style.visibility = 'hidden';
		//popisek.style.visibility = 'hidden';
	}
	else
	{
		pole.style.visibility = 'visible';
		//popisek.style.visibility = 'visible';
	}
}

function checkEmail(email) {
	var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (!filter.test(email)) { return false;	}
	else return true;}

function checkFields()
{
	var error="";
	var email=document.getElementById('email').value;
	
	if (email == "")  error += "Musíte zadat e-mail.\n";
	if (checkEmail(email) == false ) error += "E-mail v nesprávném formátu.";
	
	
	if(error=="") return true;
	else 
		{
		alert(error);
		return false;
		}
}

function checkAddress(_node)
{
	
	if(checkEmail(_node.value) == true) _node.style.color = 'green';
	if(checkEmail(_node.value) == false) _node.style.color = 'red';
}