/*!
 * jQuery Check Required Plugin
 * Checks if fields marked as required are empty
 * and show error message if they are
 *
 * Copyright (c) 2011 Dmitriy Kubyshkin (http://kubyshkin.ru)
 * Licensed under the MIT license
 */
if(jQuery) // Check if jQuery is loaded
{
  (function($) { // Making $ accessible even in noConflict
    jQuery.fn.checkRequired = function(options){
      var options = jQuery.extend({
        errorClassName: "error-field"
      },options);

      return this.each(function(){
        var hold = $(this);
      
        // Finding all form elements
        inputs = hold.find('input, select, textarea').filter('.required');
      
        // We don't know if there's an error after form changed
        inputs.bind('change', function(){
          $(this).removeClass(options.errorClassName);
        });
      
        hold.bind('submit', function(){
          // At first assuming that all went smoothly
          var returnValue = true;
        
          // Then we check each required field if it has some value
          inputs.each(function(){
            var input = $(this);
            // If field doesn't have a value
            if(input.val() == "" || input.val() == input.get(0).defaultValue)
            {
              // We make sure form won't get submitted
              returnValue = false;
              // Add appropriate css class for error
              input.addClass(options.errorClassName);
            }
            else
            {
              // Need to cleanup if form was previously had errors
              input.removeClass(options.errorClassName);
            }
          });
        
          // If there are errors we need to tell the user
          if(!returnValue)
          {
            alert("Some required fields are missing.\nPlease check your input and try again.");
          }
          return returnValue;
        });
      });
    };
  })(jQuery);
}