Plugin modification

Hi,

I am using a Hospital management system to keep record of my ayurvilla patients.

I added few form fields in the core phph file as the plugin doe not allow to add them at backend. now when i try to submit the form it shows error.

Here i am attaching the screen shot of the error, the original and customized php files as well.

1) Error image: https://www.dropbox.com/s/tey1455qfg06y3a/form%20error.png?dl=0

2) Original php file: https://www.dropbox.com/s/iwtrzd08nxrxyvl/add_patient.php?dl=0

3) Customized PHP file https://www.dropbox.com/s/uw35xxbevk5w0zj/customized%20add_patient.php?dl=0

Look forward to hearing from you guys.

Thanks.
Fasih