swift2 - Swift 2.0 doesn't let me make UIAlertAction -

this picture should enough:

i have been scouring web find answers , none else seems have problem. using xcode 7 beta 3 swift 2. can't figure out what's wrong.

thanks in advance

edit:

here's code:

func input(text:string) -> string {     say(text)     let alert:uialertcontroller = uialertcontroller(title: "goog", message: text, preferredstyle: uialertcontrollerstyle.alert)     [alert .addtextfieldwithconfigurationhandler({ (textfield: uitextfield!) -> void in     })]     var returnvalue:string = ""     let confirmaction = uialertaction(         title: "ok", style: uialertactionstyle.default) {(action) in             returnvalue = (alert.textfields[0] uitextfield).text!             return     }     return returnvalue } 

uialertcontroller *altsuccess = [uialertcontroller alertcontrollerwithtitle:@"success" message:@"login successfully" preferredstyle:uialertcontrollerstylealert];  uialertaction *oksuccess = [uialertaction                                     actionwithtitle:@"ok"                                     style:uialertactionstyledefault                                     handler:^(uialertaction * action)                                     {                                         nslog(@"%@",[dict objectforkey:@"email"]);                                         nslog(@"%@",[dict objectforkey:@"password"]);                                         [altsuccess dismissviewcontrolleranimated:yes completion:nil];                                     }];          [altsuccess addaction:oksuccess];          [self presentviewcontroller:altsuccess animated:yes completion:nil]; 

its works fine...