Remote url json data in combo box

Hi I am getting error in my code for combo box with json data. [quote] Ext.define(‚Shopware.apps.ProductField.view.detail.Window‘, { override: ‚Shopware.apps.Article.view.detail.Window‘, createDescriptionFieldSet: function() { var me = this, fields = me.callParent(arguments); fields.add({ /**** Here i want to add combo box with json data from other domain url *****/ }); return fields; } }); [/quote] How can i add that combo with json data with other domain url