How to test if a string object contains a specific text

[Boba Fonts]

Same as the thread title. For an educational program I need students to type an answer to a certain question, 'cause this one can't be done with combo boxes or checkboxes. There are many ways they could type the answer, but the "critical" words (apart from articles, prepositions, punctuation, spaces, etc.) are a few, and those words definitely must be in the answer. How can I test if a text string (or Edit Box, which I'm going to use) contains given texts? thanks

[LB]

You can convert it to lowercase with the Lower$() function, to make it case insensitive. You can then search for a string in a string with the Find() function. Both of these can be found as expressions under the Special Object -> Strings ->

[Boba Fonts]

Thanks LB.
So, just to understand how Find() works, I've tried to figure out which condition I can use with those expressions. I've tried "Compare two general values" this way but I'm certainly messing things:

Find(Lower$(Edittext$( "Edit Box" )), "clickteam", 3)
=
3

but as far as I understand it only checks if the searched text "clickteam" starts at the defined position (fourth character in this case, after three previous characters), otherwise it's false even if the string of text is indeed present somewhere.
How can I test if the string to be found is there at all, regardless of its position?

[Phi]

0 is the first character. You specify which character to begin the search on in the final parameter of Find(). If it is located, the returned value of Find will be 0+, to indicate the index of the find.
Some examples:
Find("abc","b",0) == 1
Find("abc","b",1) == 1
Find("abc","b",-1) == -1 (invalid search index - so not found)
Find("abc","b",2) == -1 (not found, as the search started on "c")
Find("abc","b",60) == -1 (invalid search index - so not found)
Find("abc","c",0) == 2
Find("abc","c",1) == 2
Find("abc","c",2) == 2

[Boba Fonts]

I test for the wanted string starting from character numer 0, i.e. in the whole text, and if it's = -1 then is false, it isn't there; if is <> -1 it has been found. Thank you all, now it's clear.