iphone - uialertview don't do action -

i have put alert view 2 buttons, buttons don't open urls. don't know error. please.

here's code:

-(ibaction)showalertview { uialertview *alert = [[uialertview alloc]                       initwithtitle:@"obrir en..."                       message:@"es pot requirir la aplicació de google maps"                       delegate:self                       cancelbuttontitle:@"millor no..."                       otherbuttontitles:@"mapes",@"google maps",nil]; [alert show]; } - (void)alertview:(uialertview *)alertview clickedbuttonatindex:(nsinteger)buttonindex { nsstring *title = [alertview buttontitleatindex:buttonindex];  if([title isequaltostring:@"mapes"]) {     uiapplication *ourapplication = [uiapplication sharedapplication];     nsstring *ourpath = @"http://maps.apple.com/?q=plaça+del+rei+43003+tarragona";     nsurl *oururl = [nsurl urlwithstring:ourpath];     [ourapplication openurl:oururl];  } if([title isequaltostring:@"google maps"]) {     uiapplication *ourapplication = [uiapplication sharedapplication];     nsstring *ourpath = @"comgooglemaps://?daddr=plaça+del+rei+43003+tarragona&directionsmode=walking";     nsurl *oururl = [nsurl urlwithstring:ourpath];     [ourapplication openurl:oururl]; }     } 

you have url encoding urlstring because contain special character.

nsstring *ourpath = @"http://maps.apple.com/?q=plaça+del+rei+43003+tarragona"; ourpath=[ourpath stringbyaddingpercentescapesusingencoding:nsutf8stringencoding];