pls help with 2 arrays searching

Question

I have 2 forms.
for example, One form has 30 textboxes which fill up with one char and another form has only one textbox which fill up with one word(5 char).
i make 2 arrays. 30 indexes of array1 and 5 indexes of array2.
i want to show the result characters in another textbox when each index of array2 is equal to each index of array1.
how to write the function()?
pls help me!!!