C sharp Program help

[rayraymason]

Need some help with my c sharp program I have a few errors that I could really use some help on. One error is that I made a checkId method to check and see if the IDS matched. If the two IDs match then it sends a message saying it cannot add the student because the ids are the same. The problem I am having is that i cannot figure out where to call this method. And the other problem i am having is that when I click the next student button it goes until the end of the array and not the last person in the list. And when I click the last student button it goes just goes straight to the end of the array and not to the last student in the array. Any help would be appreciated Thanks