Connect multiple textbox to the database in WinApp

Question

Here is my case: 
I have created 2 form which is login form, which username textbox already connected to the database and it is successfully.
When user login, it direct to the second form, and in the second form, there are multiple textbox that i have created using Array List, and it has shown.


Here is my problem:
I want to connect the textboxes in second form to the database, but it shown nothing when i run the program, i already trace the code which is the error, and the error is on when OleDBDataReader is reading, i dunno what's wrong with my code, in login form it run perfectly, but in the second form, there is an error.

Here is the link image for Login Form:https://www.dropbox.com/s/5q8pyztqy7ejupy/Capture.PNG


Here is the link image for Second Form:
https://www.dropbox.com/s/khsvh5bf1dc4c8u/Capture_2.PNG


Here is the link code for Second Form:
https://www.dropbox.com/s/rval228qyo2mwbj/Code%20for%20Second%20Form_2.docx


For the Second Form, in the column of code, it supposed to shown the autocomplete like at the Login Form.

Thank you.