login.js

$.fn.popup_handler = function(selector_to_show) {
  var self   = this;
  var target = $(selector_to_show);
  target.hide();
  var target_shown = false;
  var self_class = 'target-shown';
  var target_show = function() {
      target.show();
      target_shown = true;
      $(self).addClass(self_class);
  };
  var target_hide = function() {
      target.hide();  
      target_shown = false;
      $(self).removeClass(self_class);
  };
  target_if = function() {
    if (target_shown == false) {
      target_show();
    } else {
      target_hide();
    }
  };
  $(this).toggle(function() {
    target_if();
  }, function() {
    target_if();
  });
  $(window).click(function() {
    target_hide();
  });
  target.click(function(e){
    e.stopPropagation();
  });
};