EDIT

  function _add_js_resizable_element($selector, $y_axis_only) {

    _add_jquery_ui();

    $options = "";

    if($y_axis_only) {

      $options = "resize: function(event, ui) {

        ui.size.width = ui.originalSize.width;

        },

        handles: \"s\"";

    }

    drupal_add_js("

          jQuery(document).ready(function() {

             jQuery('" . $selector . "').resizable({". $options ."});

          });

        ",

      array(

        'type' => 'inline',

        'scope' => 'footer'

      )

    );

  }