新手Hello World中IB的连线问题...

 小弟我初学Iphone开发,
创建好Window.xib后,运行没事,但一与Window.h的控件相连线,空心的点变成实心的以后,再运行,就出现以下问题.2012-07-25 11:49:36.032 FirstWin[1896:f803] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<UIApplication 0x682b060> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key btnPress.'
*** First throw call stack:
(0x13c7022 0x1558cd6 0x13c6ee1 0x9bf022 0x930f6b 0x930edb 0x94bd50 0x23371a 0x13c8dea 0x13327f1 0x23226e 0x233eb7 0x10ce1 0x10ff8 0x1017f 0x1f183 0x1fc38 0x13634 0x12b1ef5 0x139b195 0x12ffff2 0x12fe8da 0x12fdd84 0x12fdc9b 0xfc65 0x11626 0x1ecd 0x1e35)
terminate called throwing an exception(lldb) 希望前辈们指点,提供解决方案,先谢了!