C# sign in and out program

[WMTs]

I would like to request some help on creating a c# based sign in and out form that uses an sql datbase to store people signing in and then out again

There are no errors however the form will not accept any data and the sign out form dropdown box will not populate with names of people from persons table I would like help to making this work please

I can send anyone the entire program as a zip file to play around with or help me to fix, if you sent me an e-mail, I currently work with visual studio, which displays errors however I cannot seem to find any help with a similar system to the one I am creating, The system is local based and is currently using a hardcoded username and password to get to the admin page as only one person will be using this system when created, I have also put comments on what things to and what need fixing that I have currently found Thanks in advance, Tom

The images are below of my current code and the forms with them