Sorry...
Edit javascript in the same file "item-post" in <head> tag...
<script type="text/javascript">
twitter_theme.text_select_subcategory = "<?php _e('Select a subcategory...', 'twitter') ; ?>" ;
twitter_theme.category_selected_id = "<?php echo item_selected_category_id() ; ?>" ;
twitter_theme.subcategory_selected_id = "<?php echo item_selected_subcategory_id() ; ?>" ;
twitter_theme.max_number_photos = <?php echo osc_max_images_per_item() ; ?> ;
twitter_theme.photo_remove_text = "<?php _e('Remove', 'twitter') ; ?>" ;
twitter_theme.max_images_fields_txt = "<?php _e('Sorry, you have reached the maximum number of images per ad', 'twitter') ; ?>" ;
twitter_theme.country_select_id = "<?php echo get_country_id((osc_item() != null) ? osc_item() : array()) ; ?>" ;
twitter_theme.region_select_id = "<?php echo get_region_id((osc_item() != null) ? osc_item() : array()) ; ?>" ;
twitter_theme.city_select_id = "<?php echo get_city_id((osc_item() != null) ? osc_item() : array()) ; ?>" ;
twitter_theme.ajax_url = "<?php echo osc_base_url(true) . '?page=ajax' ; ?>" ;
twitter_theme.text_select_country = "<?php _e('Select a country...', 'twitter') ; ?>" ;
twitter_theme.text_select_region = "<?php _e('Select a region...', 'twitter') ; ?>" ;
twitter_theme.text_select_city = "<?php _e('Select a city...', 'twitter') ; ?>" ;
twitter_theme.text_no_regions = "<?php _e('No regions available', 'twitter') ; ?>" ;
twitter_theme.text_no_cities = "<?php _e('No cities available', 'twitter') ; ?>" ;
twitter_theme.page = "form" ;
twitter_theme.item_id = "" ;
</script>