View Compilation Error

327411_0_1266.cpp: In function `int main()':
327411_0_1266.cpp:21: error: call of overloaded `abs(double&)' is ambiguous
GCC/bin/../lib/gcc/mingw32/3.4.2/../../../../include/stdlib.h:363: note: candidates are: int abs(int)
327411_0_1266.cpp:10: note:                 double abs(double)
GCC/bin/../lib/gcc/mingw32/3.4.2/../../../../include/c++/3.4.2/cmath:97: note:                 long double std::abs(long double)
GCC/bin/../lib/gcc/mingw32/3.4.2/../../../../include/c++/3.4.2/cmath:93: note:                 float std::abs(float)
GCC/bin/../lib/gcc/mingw32/3.4.2/../../../../include/c++/3.4.2/cmath:89: note:                 double std::abs(double)
GCC/bin/../lib/gcc/mingw32/3.4.2/../../../../include/c++/3.4.2/cstdlib:153: note:                 long long int __gnu_cxx::abs(long long int)
GCC/bin/../lib/gcc/mingw32/3.4.2/../../../../include/c++/3.4.2/cstdlib:123: note:                 long int std::abs(long int)