Is there a function in GDL to find a specific character in a sentence?

[LeeJaeYoung]

Is there a function in GDL to find a specific character in a sentence?
(I am trying to find out if there is a letter "am" in the sentence "I am a boy.")

[Miha Nahtigal · Accepted solution]

STRSTR (string_expression1, string_expression2[, case_insensitivity])
Returns the (integer) position of the first appearance of the second string in the first string. If the first string doesn’t contain the second one,
the function returns 0.
Note: In case string_expression2 is an empty string, the function returns 1.
case_insensitivity:
0 or not set: Case sensitive
1: Case insensitive

[LeeJaeYoung]

Thank you so much

ns = STRSTR ("I am a Boy", "am")
return 3