iphone - NSString out of scope problem? -

i'm pulling hair out, must simple problem, can't see it.

i'm trying assign value variable text field.

in h file have

nsstring *currentpass;  @property (nonatomic, retain) nsstring *currentpass; 

my m file.

@synthesize currentpass; - (void)alertview:(uialertview *)alertview willdismisswithbuttonindex:         (nsinteger)buttonindex{  if (alertview.tag == alertpasswordask) {     uitextfield* thetextfield = ((uitextfield*)[alertview viewwithtag: 5]);     currentpass = [nsstring stringwithformat:@"%@", thetextfield.text];     if ([thetextfield isediting]) {         [thetextfield resignfirstresponder];     }  } }  - (void)alertview:(uialertview *)alertview      diddismisswithbuttonindex:(nsinteger)buttonindex{      nslog(@"diddismisswithbuttonindex tag=%i", alertview.tag); if (alertview.tag == alertpasswordask) {     if(buttonindex == 1){         nsuserdefaults *mydefaults = [nsuserdefaults standarduserdefaults];         nsstring *strpassword = [nsstring alloc];         strpassword = [mydefaults stringforkey:@"pass"];               // #########  error occurs here #########         nslog(@"currentpass=%@ strpassword=%@", currentpass, strpassword);          if (![currentpass isequaltostring:strpassword]) { 

[6337:207] diddismisswithbuttonindex tag=10 current language:  auto; objective-c (gdb) continue program received signal:  “exc_bad_access”. (gdb) bt #0  0x02894903 in objc_msgsend () #1  0x00000000 in ?? () 

you need retain object assign currentpass:

self.currentpass = [nsstring stringwithformat:@"%@", thetextfield.text];