TxtFindString??

[Horace Ho]

I tried to use TxtFindString() but failed. The code is:

 {
  Boolean f; ULong outPos; Word outLen;
  f = TxtFindString ("012345678", "4567", &outPos, &outLen);
  f = TxtFindString ("012345678", "0123", &outPos, &outLen);
  f = TxtFindString ("abcdefghi", "defg", &outPos, &outLen);
  f = TxtFindString ("abcdefghi", "abcd", &outPos, &outLen);
 }

The results of 4 lines (shown in debugger) for f, outPos, and outLen are:

1) 0, 0, 0
2) 1, 0, 4
3) 0, 0, 0
4) 0, 0, 0

Any hint? 

Thanks
horace