View Compilation Error

0_0_24393358_1759.cpp: In function 'double Merge(int, int)':
0_0_24393358_1759.cpp:40:17: error: 'low' was not declared in this scope
  for(i=mid-1;i>=low;i--)
                 ^
0_0_24393358_1759.cpp:51:17: error: 'high' was not declared in this scope
  for(i=mid+1;i<=high;i++)
                 ^