function fnAddAlias(strAlias, strUsername) {
  // Sanitize input
  strCheckedAlias = strAlias.replace(/[^a-zA-Z0-9_.-]*/g, '');
  strCheckedAlias = strCheckedAlias.replace(/\.+/g, '.');
  while (strCheckedAlias.charAt(strCheckedAlias.length - 1) == '.') {
    strCheckedAlias = strCheckedAlias.substring(0, strCheckedAlias.length - 1);
  }
  while (strCheckedAlias.charAt(0) == '.') {
    strCheckedAlias = strCheckedAlias.substring(1, strCheckedAlias.length);
  }

  if (strCheckedAlias != '' && strAlias == strCheckedAlias) {
    // Input is sane; start adding alias
    objAllAliases = document.getElementById('allaliases');
    objNewAlias = document.getElementById('newalias');
    intTimestamp = new Date().getTime();

    // Check if alias already exists, if so provide token feedback to user and abort adding alias
    for (i = 0; i < objAllAliases.options.length; i++) {
      if (objAllAliases.options[i].value == strCheckedAlias + '.' + strUsername) {
        objAllAliases.options.selectedIndex = -1;
        objAllAliases.options[i].selected = true;
        objNewAlias.value = '';
        return false;
      }  
    }

    objAllAliases.options[objAllAliases.options.length] = new Option(strCheckedAlias + '.' + strUsername + '@spamasaurus.com', strCheckedAlias + '.' + strUsername);
    objAllAliases.options[objAllAliases.options.length - 1].id = intTimestamp;
    objAllAliases.options[objAllAliases.options.length - 1].className = 'new';

    fnSortOptions(objAllAliases);

    objAllAliases.options.selectedIndex = -1;
    document.getElementById(intTimestamp).selected = 'true';

    objNewAlias.value = '';
  } else if (strCheckedAlias != '' && strAlias != strCheckedAlias) {
    // Input is NOT sane; Suggest sanitized input to user - with option to accept suggestion or cancel adding alias
    fnShowError(true);

    document.getElementById('errorsub').innerHTML = 'Ongeldigde tekens';
    document.getElementById('errordesc').innerHTML = 'De opgegeven alias <strong>' + strAlias + '.' + strUsername + '</strong> bevat ongeldige tekens.<br />Klik op <strong>doorgaan</strong> om de alias automatisch te corrigeren naar <strong>' + strCheckedAlias + '.' + strUsername + '</strong> en toe te voegen.';
    document.getElementById('continue').onclick = function() {fnAddAlias(strCheckedAlias, strUsername); fnShowError(false);};
    document.getElementById('cancel').onclick = function() {document.getElementById('newalias').value = ''; fnShowError(false);};
  } else {
    // No input or entirely invalid input, no action needed
    document.getElementById('newalias').value = '';
  }
}

function fnDeleteAliases() {
  objAllAliases = document.getElementById('allaliases');
  arrAllAliases = new Array();

  for (i = 0; i < objAllAliases.options.length; i++) {
    if (objAllAliases.options[i].selected == true) {
      arrAllAliases.push(objAllAliases.options[i].value);
    }
  }

  if (arrAllAliases.length == 0) {
    // Nothing selected; nothing will be deleted
    exit;
  } else if (arrAllAliases.length == 1) {
    blnAnswer = confirm('De alias "' + arrAllAliases[0] + '@spamasaurus.com" echt verwijderen?' + "\n\n" + 'Mail gericht aan dit adres zal voortaan niet meer worden geaccepteerd.');
  } else if (arrAllAliases.length > 1) {
    blnAnswer = confirm('Geselecteerde ' + arrAllAliases.length + ' aliassen echt verwijderen?' + "\n\n" + 'Mail gericht aan deze adressen zal voortaan niet meer worden geaccepteerd.');
  }

  if (blnAnswer == true) {
    for (i = objAllAliases.options.length -1; i >= 0; i--) {
      if (objAllAliases.options[i].selected == true) {
        objAllAliases.remove(i);
      }
    }
  }
}

function fnSubmitChanges() {
  objAllAliases = document.getElementById('allaliases');
  arrAllAliases = new Array();
  arrAllAliases['size'] = objAllAliases.options.length;
  arrAllAliases['data'] = new Array();

  for (i = 0; i < objAllAliases.options.length; i++) {
    arrAllAliases['data'].push(objAllAliases.options[i].value);
  }  

  document.getElementById('data').value = fnSerialize(arrAllAliases);
}

function fnSortOptions(objSelect) {
  var arrToSort = new Array();

  for (i = 0; i < objSelect.options.length; i++) {
    arrToSort[i] = new Array();
    arrToSort[i][0] = objSelect.options[i].text;
    arrToSort[i][1] = objSelect.options[i];
  }

  arrToSort.sort();

  objSelect.options.length = 0;

  for (i = 0; i < arrToSort.length; i++) {
    objSelect.options.add(arrToSort[i][1]);
  }
}

function fnShowError(blnShowError) {
  if (blnShowError == true) {
    document.getElementById('content').style.display = 'none';
    document.getElementById('error').style.display = 'block';
  } else if (blnShowError == false) {
    document.getElementById('content').style.display = 'block';
    document.getElementById('error').style.display = 'none';
  }
}

function fnInstallXPI (event) {
  var objParameters = {
    "Spamasaurus Rex": {
      URL: event.target.href,
      Hash: event.target.getAttribute("hash"),
      toString: function () { return this.URL; }
    }
  };
  InstallTrigger.install(objParameters);

  return false;
}

function fnSerialize (mixed_value) {
    // http://kevin.vanzonneveld.net
    // +   original by: Arpad Ray (mailto:arpad@php.net)
    // +   improved by: Dino
    // +   bugfixed by: Andrej Pavlovic
    // +   bugfixed by: Garagoth
    // +      input by: DtTvB (http://dt.in.th/2008-09-16.string-length-in-bytes.html)
    // +   bugfixed by: Russell Walker (http://www.nbill.co.uk/)
    // +   bugfixed by: Jamie Beck (http://www.terabit.ca/)
    // %          note: We feel the main purpose of this function should be to ease the transport of data between php & js
    // %          note: Aiming for PHP-compatibility, we have to translate objects to arrays
    // *     example 1: fnSerialize(['Kevin', 'van', 'Zonneveld']);
    // *     returns 1: 'a:3:{i:0;s:5:"Kevin";i:1;s:3:"van";i:2;s:9:"Zonneveld";}'
    // *     example 2: fnSerialize({firstName: 'Kevin', midName: 'van', surName: 'Zonneveld'});
    // *     returns 2: 'a:3:{s:9:"firstName";s:5:"Kevin";s:7:"midName";s:3:"van";s:7:"surName";s:9:"Zonneveld";}'
 
    var _getType = function (inp) {
        var type = typeof inp, match;
        var key;
        if (type == 'object' && !inp) {
            return 'null';
        }
        if (type == "object") {
            if (!inp.constructor) {
                return 'object';
            }
            var cons = inp.constructor.toString();
            match = cons.match(/(\w+)\(/);
            if (match) {
                cons = match[1].toLowerCase();
            }
            var types = ["boolean", "number", "string", "array"];
            for (key in types) {
                if (cons == types[key]) {
                    type = types[key];
                    break;
                }
            }
        }
        return type;
    };
    var type = _getType(mixed_value);
    var val, ktype = '';
    
    switch (type) {
        case "function": 
            val = ""; 
            break;
        case "boolean":
            val = "b:" + (mixed_value ? "1" : "0");
            break;
        case "number":
            val = (Math.round(mixed_value) == mixed_value ? "i" : "d") + ":" + mixed_value;
            break;
        case "string":
            val = "s:" + encodeURIComponent(mixed_value).replace(/%../g, 'x').length + ":\"" + mixed_value + "\"";
            break;
        case "array":
        case "object":
            val = "a";
            /*
            if (type == "object") {
                var objname = mixed_value.constructor.toString().match(/(\w+)\(\)/);
                if (objname == undefined) {
                    return;
                }
                objname[1] = this.fnSerialize(objname[1]);
                val = "O" + objname[1].substring(1, objname[1].length - 1);
            }
            */
            var count = 0;
            var vals = "";
            var okey;
            var key;
            for (key in mixed_value) {
                ktype = _getType(mixed_value[key]);
                if (ktype == "function") { 
                    continue; 
                }
                
                okey = (key.match(/^[0-9]+$/) ? parseInt(key, 10) : key);
                vals += this.fnSerialize(okey) +
                        this.fnSerialize(mixed_value[key]);
                count++;
            }
            val += ":" + count + ":{" + vals + "}";
            break;
        case "undefined": // Fall-through
        default: // if the JS object has a property which contains a null value, the string cannot be unserialized by PHP
            val = "N";
            break;
    }
    if (type != "object" && type != "array") {
        val += ";";
    }
    return val;
}