Swift 2 if , else 2 string error :)

Im trying to 2 string is equal gives me error my codes here. help pls. thank you.

  let urlString = webView.stringByEvaluatingJavaScriptFromString("document.URL")! as String


        urlString.startIndex // first index
        urlString.endIndex // end index

        urlString.startIndex.distanceTo(urlString.endIndex) // string length
        urlString.characters.count // string length

       var look =  urlString[urlString.startIndex.advancedBy(21)]

        var kontrol = "https://www.adobe.com"


        if look == kontrol {



        }

I want to find my urlStrings first 21 char i wrote codes looking good but later i want to do if else if look = kontrol

help pls.

Im using swift 2