         }
         
         // Generate the url
-        let requestUrlString = url + qMark + visualFeatures + computedDetails
+        let requestUrlString = url + qMark + computedVisualFeatures + computedDetails
         let requestUrl = NSURL(string: requestUrlString)
 
         

     - parameter visualFeatures, details: Read more about those [here](https://dev.projectoxford.ai/docs/services/56f91f2d778daf23d8ec6739/operations/56f91f2e778daf14a499e1fa)
     - parameter completion: Once the request has been performed the response is returend as a JSON Object in the completion block.
     */
    func recognizeCharactersOnImageUrl(imageUrl: String, visualFeatures: String = "", details: String = "",completion: (response: JSON) -> Void) throws {
     
        // Create the Query parameters
        var computedVisualFeatures: String {
            if visualFeatures.isEmpty != false {
                return  "visualFeatures=" + visualFeatures
            }
            else {
                return ""

        
        var computedDetails: String {
            
            if details != .None {
                return "details=" + details.rawValue
            }
            else {
                return ""
