function elem(elementName) {
  return document.getElementById(elementName);
}

function containsElement(elementArray, element) {
  for (var index = 0; index < elementArray.length; index++) {
    if (elementArray[index] == element) {
      return true;
    }
  }
  return false;
}

function show(elementName) {
  elem(elementName).style.display = '';
}

function showBlock(elementName) {
  elem(elementName).style.display = 'block';
}

function hide(elementName) {
  elem(elementName).style.display = 'none';
}

function showElements(elementNames) {
  for (var index = 0; index < elementNames.length; index++) {
    showBlock(elementNames[index]);
  }
}

function showElementsInline(elementNames) {
  for (var index = 0; index < elementNames.length; index++) {
    show(elementNames[index]);
  }
}

function hideElements(elementNames) {
  for (var index = 0; index < elementNames.length; index++) {
    hide(elementNames[index]);
  }
}

function enable(elementName) {
  elem(elementName).disabled = false;
}

function disable(elementName) {
  elem(elementName).disabled = true;
}

function showError(fieldKey, message) {
  if (message) {
    elem(fieldKey + "ErrorMessage").innerHTML = message;
  }
  showBlock(fieldKey + "ErrorMessage");
  elem(fieldKey + "ErrorBox").className = "errorbox-bad";
}

function hideError(fieldKey) {
  hide(fieldKey + "ErrorMessage");
  elem(fieldKey + "ErrorBox").className = "errorbox-good";
}


function getValue(element) {
  if (element == undefined) {
    return null;
  }
  if (element.value) {

    return element.value;
  } else if (element.length) {
    if (element.options) {

      return element.options[element.selectedIndex].value;
    } else {

      for (var index = 0; index < element.length; index++) {
        if (element[index].checked) {
          return element[index].value;
        }
      }
    }
  }
  return null;
}

function val(elementName) {
  return getValue(elem(elementName));
}

function trim(str) {
  if (str == null) {
    return '';
  }
  return str.replace(/^\s+/,'').replace(/\s+$/,'');
}

function validateUrlSyntax(url, allowRelativeUrls) {
  url = trim(url);
  if (url.length > 0){
    if (allowRelativeUrls) {
      return (url != "http://") && (url != "https://"); 
    } else {
      return ((url.substr(0,7) == "http://") && (url.length > 7)
          || ((url.substr(0,8) == "https://")) && (url.length > 8));
    }
  }

  return false;
}