function clearInput() {
	  if(!emailValidation()) {
	    document.getElementById('newsletter_subscriber_email').value = '';
		}
	}
	
	function insertDefaultInputText() {
	  if(document.getElementById('newsletter_subscriber_email').value == '') {
	    document.getElementById('newsletter_subscriber_email').value = 'Podaj swój adres e-mail...';
		}
		emailValidation();
	}
	
	function showValidationInfo(info) {
	  var infoBox;
	  switch(info) {
		  case 'format': {infoBox = document.getElementById('validationInfo'); break;}
			case 'OK': {infoBox = document.getElementById('validationOK'); break;}
			default: { break; }
		}
		infoBox.style.display = 'block';
	}
	function hideValidationInfo(info) {
	  var infoBox;
	  switch(info) {
		  case 'format': {infoBox = document.getElementById('validationInfo'); break;}
			case 'OK': {infoBox = document.getElementById('validationOK'); break;}
			default: { break; }
		}
		infoBox.style.display = 'none';
	}
	
  function emailValidation() {
   var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{1,3})$/;
   var address = document.getElementById('newsletter_subscriber_email').value;
   if(reg.test(address) == false) {
     hideValidationInfo('OK');
			showValidationInfo('format');
			return false;
   } else { 
	   hideValidationInfo('format'); 
		 showValidationInfo('OK');
		 return true;
	 }
}