iphone - How to add a callout having one title -

my map code:

if (latitude != [nsnull null] && longitude != [nsnull null])     {     location.latitude=[latitude doublevalue];     location.longitude=[longitude doublevalue];     myannotationview *newannotation=[[myannotationview alloc]initwithtitle:[nsstring stringwithformat:@"bus-%d",h] latitude:location.latitude longitude:location.longitude];     [self.mymap addannotation:newannotation];     mymap.maptype=mkmaptypestandard;     [mymap setcentercoordinate:location animated:yes];     mkcoordinateregion region = mkcoordinateregionmakewithdistance(location,1000,1000);     [mymap setregion:region animated:yes];      }  -(void)locationmanager:(cllocationmanager *)manager didupdatetolocation:(cllocation *)newlocation fromlocation:(cllocation *)oldlocation {  location.latitude=newlocation.coordinate.latitude; location.longitude=newlocation.coordinate.longitude; myannotationview *newannotation=[[myannotationview alloc]initwithtitle:[nsstring stringwithformat:@"bus-%d",h] latitude:location.latitude longitude:location.longitude]; [self.mymap addannotation:newannotation]; mkcoordinateregion region = mkcoordinateregionmakewithdistance(location,1000, 1000); [mymap setregion:region animated:yes]; [mymap setcentercoordinate:newlocation.coordinate animated:yes]; } 

mkannotationview.h

@implementation myannotationview @synthesize title,coordinate; -(id)initwithtitle:(nsstring *)newtitle latitude:(float)newlatitude longitude:(float)newlongitude {      if (self=[super init])      {         title=newtitle;         coordinate.latitude=newlatitude;         coordinate.longitude=newlongitude;      }     return  self; } 

how can add callout title? it's not popping out when click on annotation. when click, following thread error

exc_breakpoint(code=exc_1386+bpt,subcode 0.0)