[FIX] point_of_sale: fixed some bugs with the scanner

bzr revid: fva@openerp.com-20120816155801-oexzurmsgfiv2xt9

addons/point_of_sale/static/src/js/pos_devices.js

@@ -298,7 +298,7 @@ function openerp_pos_devices(instance,module){ //module is instance.point_of_sal
         // returns true if the ean is a valid EAN codebar number by checking the control digit.
         // ean must be a string
         check_ean: function(ean){
-            return ean_checksum(ean) === Number(ean[ean.length-1]);
+            return this.ean_checksum(ean) === Number(ean[ean.length-1]);
         },
         // returns a valid zero padded ean13 from an ean prefix. the ean prefix must be a string.
         sanitize_ean:function(ean){

addons/point_of_sale/static/src/js/pos_screens.js

@@ -160,7 +160,7 @@ function openerp_pos_screens(instance, module){ //module is instance.point_of_sa
         // there's an error.
         barcode_product_action: function(ean){
             var self = this;
-            if(pos_widget.scan_product(ean)){
+            if(self.pos.scan_product(ean)){
                 self.pos.proxy.scan_item_success(ean);
                 if(self.barcode_product_screen){ 
                     self.pos_widget.screen_selector.set_current_screen(self.barcode_product_screen);