Why does this error occur?
<p>i am parsing the data from web service.After parsing the few records it gives this error.Somebody please the tell me what the reason behind this error?</p>

<pre><code>[NSXMLParser length]: unrecognized selector sent to instance 0x6e6d340



*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSXMLParser length]: unrecognized selector sent to instance 0x6e6d340'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x026c4919 __exceptionPreprocess + 185
    1   libobjc.A.dylib                     0x028125de objc_exception_throw + 47
    2   CoreFoundation                      0x026c642b -[NSObject(NSObject) doesNotRecognizeSelector:] + 187
    3   CoreFoundation                      0x02636116 ___forwarding___ + 966
    4   CoreFoundation                      0x02635cd2 _CF_forwarding_prep_0 + 50
    5   Foundation                          0x001053e9 -[NSXMLParser parse] + 104
    6   SexOffenders                        0x00009c30 -[UserProfileVC connectionDidFinishLoading:] + 565
    7   Foundation                          0x0006e666 -[NSURLConnection(NSURLConnectionReallyInternal) sendDidFinishLoading] + 108
    8   Foundation                          0x0006e5bf _NSURLConnectionDidFinishLoading + 133
    9   CFNetwork                           0x02c569f1 _ZN19URLConnectionClient23_clientDidFinishLoadingEPNS_26ClientConnectionEventQueueE + 285
    10  CFNetwork                           0x02d1fc72 _ZN19URLConnectionClient26ClientConnectionEventQueue33processAllEventsAndConsumePayloadEP20XConnectionEventInfoI12XClientEvent18XClientEventParamsEl + 402
    11  CFNetwork                           0x02d200ea _ZN19URLConnectionClient26ClientConnectionEventQueue33processAllEventsAndConsumePayloadEP20XConnectionEventInfoI12XClientEvent18XClientEventParamsEl + 1546
    12  CFNetwork                           0x02d200ea _ZN19URLConnectionClient26ClientConnectionEventQueue33processAllEventsAndConsumePayloadEP20XConnectionEventInfoI12XClientEvent18XClientEventParamsEl + 1546
    13  CFNetwork                           0x02c4bdfe _ZN19URLConnectionClient13processEventsEv + 100
    14  CFNetwork                           0x02c4bc95 _ZN17MultiplexerSource7performEv + 247
    15  CoreFoundation                      0x026a5d7f __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 15
    16  CoreFoundation                      0x026041dd __CFRunLoopDoSources0 + 333
    17  CoreFoundation                      0x026037c6 __CFRunLoopRun + 470
    18  CoreFoundation                      0x02603280 CFRunLoopRunSpecific + 208
    19  CoreFoundation                      0x026031a1 CFRunLoopRunInMode + 97
    20  GraphicsServices                    0x02f292c8 GSEventRunModal + 217
    21  GraphicsServices                    0x02f2938d GSEventRun + 115
    22  UIKit                               0x002dab58 UIApplicationMain + 1160
    23  SexOffenders                        0x00002198 main + 102
    24  SexOffenders                        0x00002129 start + 53
)
terminate called after throwing an instance of 'NSException'
</code></pre>
