This function allows you to retrieve the index of a test condition (flag)
when the name of the test is given as input. The array to which the index can
be applied is FLAG(). Used in user routines it gives you the ability to
be more code independent. The index of a test condition is established during
the compilation of the test file. From that point on it will not change until
the next test compilation. This means the index can be retrieved only once i.e.
after each test compilation. To do so, it is a good practice to search for it
once during the first pass through the user routine. Some system flags are
provided to allow you detect a new test compilation. newtst1, newtst2
are set to .TRUE. after each test compilation. These are available to you for
this purpose.
F The function name must be declared as LOGICAL*1 parameter.
index = TestIX (test_condition_name)