/**
 * formvalidation.js:
 *
 * Some of these function borrowed code from the book
 * Designing with Javascript pages 64-68
 **/

// Check for valid email address using regular expressions
function isEmail(elm) {
  var pattern = /^[a-zA-Z0-9\- ]+\@[a-zA-Z0-9 \-\.]+\.([a-zA-Z]{2,3})$/;
  if (pattern.test(elm.value)) {
    return true;
  }
  else
  {
    return false;
  }
}

// Check for blank fields
function isFilled(elm) {
  if (elm.value == "" || elm.value == null) {
    return false;
  }
  else {
    return true;
  }
}

// Check for numbers only using regular expressions
function isInt(elm) {
  var pattern = /[^0-9]/;
  if (pattern.test(elm.value)) {
    return false;
  }
  else
  {
    return true;
  }
}

// Check for letters only using regular expressions
function isAlpha(elm) {
  var pattern = /[^a-zA-Z]/;
  if (pattern.test(elm.value)) {
    return false;
  }
  else
  {
    return true;
  }
}

// Check for phone number using regular expressions
function isPhone(elm) {
  var pattern = /[0-9]{3}-[0-9]{3}-[0-9]{4}/;
  if (pattern.test(elm.value)) {
    return true;
  }
  else
  {
    return false;
  }
}

// Check for option with value of 0
function optionSelected(elm) {
  if (elm.value == 0) {
    return false;
  }
  else {
    return true;
  }
}

// Check for field length
function isLongEnough(elm, minlength) {
  if (elm.value.length < minlength) {
    return false;
  }
  else {
    return true;
  }
}