Adding map by AJAX

Hello, I'm writing a module where i must load map my AJAX. my code work fine, and map are loaded, but not themized into page. I see only Javascript is required to view this map..
This is some extract of my code:

function mymodule_menu($may_cache) {
  $items = array();
  if (!$may_cache) { //remove ! once debug is overn
    $items[] = array(
      'path'                  => 'mymodule/map', 
      'callback'              => '_mymodule_map',
      'type'                  => CALLBACK,
      'access'                => true, //give appropriate permissions
    );
  }
  return $items;
}

function _mymodule_map() {

$map = array(
  'id' => 'mymodule_1',
  'maptype' => 'Map',
  'width' => '400px',
  'height' => '400px',
  'latitude' => 12.345,
  'longitude' => 12.345,
  'zoom' => 4,
  'align' => 'left',
  'controltype' => 'Large',
  'mtc' => 'standard',
  'behavior' => array(
    'locpick' => FALSE,
    'nodrag' => FALSE,
    'nokeyboard' => TRUE,
    'overview' => TRUE,
    'scale' => TRUE,
  ),
  'markers' => array(),
);

  $output .= theme('gmap', array('#settings' => $map));
  
  print $output;
  exit();
}

and into JS:

$(document).ready(function () {
  $.get(
    '/mymodule/map',
    {},
    function (data) {
      $('#showMap').html(data);
    }
  )
});

into div with id showMap code appair correctly:

<div id="gmap-mymodule_1-gmap0" style="width: 400px; height: 400px;" class="0gmap gmap-map gmap-mymodule_1-gmap"
 id="gmap-mymodule_1-gmap0">Javascript is required to view this map.</div><script type="text/javascript"
>

/* <![CDATA[ */

Drupal.extend({ settings: { "gmap": { "mymodule_1": { "width": "400px", "height": "400px", "zoom"
: 4, "maxzoom": "17", "controltype": "Large", "align": "left", "maptype": "Map", "mtc": "standard", "baselayers"
: { "maptype": "Map", "Map": 1 }, "styles": { "line_default": [ "0000ff", "5", "45", null, null ], "poly_default"
: [ "000000", "3", "25", "ff0000", "45" ] }, "line_colors": [ "#00cc00", "#ff0000", "#0000ff" ], "behavior"
: { "locpick": false, "nodrag": false, "nokeyboard": true, "overview": true, "scale": true }, "markermode"
: "0", "id": "location_cck_1", "latitude": 12.345, "longitude": 12.345, "markers": [  ] } } } });
/* ]]> */
</script>

but map don't appair. I thik is a problem about JS, gmap don't load map because code is loaded after gmap.js ready function, someone can help me and suggest what's the function i must call to show map?

tks
Mavimo