Javascript Validation

form_validation.js

function validate_required_field(id, err_msg, parent_selector) {
  var error_message = err_msg || "Can't be left blank";
  var parent_selector = parent_selector || "li";
  var $field = $(id).find('input, select, textarea');
  var field_val = $field.val();
  //log(id);
  var $error = $field.parents(parent_selector).first().find('.error');
  if($.trim(field_val) == '' || $.trim(field_val) == '0') {
    $error.text(error_message);
    return false;
  } else {
    $error.text('');
    return true;
  }
}
function validate_field_with_format(id, format, err_msg, parent_selector) {
  var error_message = err_msg || "Field Value is not valid";
  var parent_selector = parent_selector || "li";
  var $field = $(id).find('input, select, textarea');
  var field_val = $field.val();
  //log($(id).val());
  var $error = $field.parents(parent_selector).first().find('.error');
  if(!format.test(field_val)) {
    $error.text(error_message);
    return false;
  } else {
    $error.text('');
    return true;
  }
}