listeners: {
beforepropertychange: function(source, recordId, value, oldValue){
if(recordId == 'BRAND_NAME'){
var record = this.getStore().getById(recordId);
this.suspendEvents();
record.set("value", cmbBrandEdit.store.getAt(cmbBrandEdit.store.find('BRAND_ID', value)).get('BRAND_NAME'));
record.commit();
this.resumeEvents();
return false;
}
} 
}