(gdb) bt
#0  0xffffe430 in __kernel_vsyscall ()
#1  0xb7822441 in raise () from /lib/libc.so.6
#2  0xb7823b82 in abort () from /lib/libc.so.6
#3  0xb785d9e5 in ?? () from /lib/libc.so.6
#4  0xb7863821 in ?? () from /lib/libc.so.6
#5  0xb7865088 in ?? () from /lib/libc.so.6
#6  0xb786816d in free () from /lib/libc.so.6
#7  0xb7a3dbb1 in operator delete(void*) () from /usr/lib/gcc/i686-pc-linux-gnu/4.4.4/libstdc++.so.6
#8  0xb7a1a54d in std::string::_Rep::_M_destroy(std::allocator<char> const&) () from /usr/lib/gcc/i686-pc-linux-gnu/4.4.4/libstdc++.so.6
#9  0xb7a1beac in std::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string() () from /usr/lib/gcc/i686-pc-linux-gnu/4.4.4/libstdc++.so.6
#10 0x0804992c in addressBook::display (this=0x8067f58, con=0x804e568) at addressBook_v2.cpp:159
#11 0x0804a422 in main () at addressBook_v2.cpp:285