[chiactivate]

I'm trying to change the button text "modify" into "modify shipping"

at check out screen (step 2 of 2).

This is the code: button_title=$lng.lbl_modify

I've also found this source code

catalogs.skin = "/~chiactiv/sdcart/skin1";
var lng_labels = new Array();
lng_labels['lbl_additional_information'] = 'Additional information';
lng_labels['lbl_address'] = 'Address';
lng_labels['lbl_and'] = 'and';
lng_labels['lbl_anonymous'] = 'anonymous';
lng_labels['lbl_applied_giftcerts'] = 'Applied Gift Certificates';
lng_labels['lbl_arb_account'] = 'DHL/Airborne account';
lng_labels['lbl_authentication'] = 'Authentication';
lng_labels['lbl_billing_address'] = 'Billing Address';
..
..
lng_labels['lbl_information'] = 'Information';
lng_labels['lbl_items'] = 'Items';
lng_labels['lbl_last_name'] = 'Last Name';
lng_labels['lbl_logoff'] = 'Log out';
lng_labels['lbl_modify'] = 'Modify';

Where can I change the value of these var lng_labels?