function openFrame() {	
  document.getElementById('send-to-friends-frame').style.display = 'block';
  document.getElementById('send-to-friends-start').style.display = 'none';
  document.getElementById('stf-my-name').focus();
}

function cancelSend() {
  document.getElementById('send-to-friends-frame').style.display = 'none';
  document.getElementById('send-to-friends-start').style.display = 'block';
}

function clearFields() {
  document.getElementById('stf-my-name').value = '';
  document.getElementById('stf-my-email').value = '';
  document.getElementById('stf-friend1-email').value = '';
  document.getElementById('stf-friend2-email').value = '';
  document.getElementById('stf-friend3-email').value = '';
  document.getElementById('stf-friend4-email').value = '';
  document.getElementById('stf-friend5-email').value = '';
  document.getElementById('stf-security-code').value = '';
  document.getElementById('stf-my-name').focus();
}

function goSend() {
  if (document.getElementById('stf-my-name').value == '') {
    alert('Please enter your name!');
	document.getElementById('stf-my-name').focus();
	return;
  }
  else if (document.getElementById('stf-my-email').value == '') {
    alert('Please enter your e-mail address!');
	document.getElementById('stf-my-email').focus();
	return;
  }
  else if (document.getElementById('stf-friend1-email').value == '') {
    alert('Please enter friend\'s e-mail address!');
	document.getElementById('stf-friend1-email').focus();
	return;
  }
  else if (document.getElementById('stf-security-code').value == '') {
    alert('Please enter security code!');
	document.getElementById('stf-security-code').focus();
	return;
  }
  
  var enc_code = document.getElementById('stf-security-code-enc').value;
  var code = '';
  
  for (i = 0; i < enc_code.length; i++) {
    if (!(i % 2)) code = code +  (enc_code.substring(i, i+2) / 9)
  }
  
  if (code == document.getElementById('stf-security-code').value) 
    startSend()
  else {
    alert('You have entered wrong security code!');
	document.getElementById('stf-security-code').value = '';
	document.getElementById('stf-security-code').focus();
  }
}

function startSend() {
  var u = document.location;
  var a = document.getElementById('stf-product').value;
  var n = document.getElementById('stf-my-name').value;
  var e = document.getElementById('stf-my-email').value;
  var f1 = document.getElementById('stf-friend1-email').value;
  var f2 = document.getElementById('stf-friend2-email').value;
  var f3 = document.getElementById('stf-friend3-email').value;
  var f4 = document.getElementById('stf-friend4-email').value;
  var f5 = document.getElementById('stf-friend5-email').value;    
  $.ajax({
    url: 'recommend-to-friends.asp',
    type: 'GET',
	data: ({u : u, a : a, n : n, e : e, f1 : f1, f2 : f2, f3 : f3, f4 : f4, f5 : f5 }),
    error: function(){
        alert('Message was not sent due to an error. Please, try again!');
        clearFields();
        cancelSend();
    },
    success: function(response){
        if (response != '') {
          if (response == 'SENT OK') {
  	        alert('Message was successfully sent to your friends. Thank you!');
	        clearFields();
            cancelSend();
	      }
	      else if ((response == 'SENT ERROR') || (response == 'ERROR')) {
  	        alert('Message was not sent due to an error. Please, try again!');
	      }  
        }
    }
  });  
}