Firstly, I need to validate the serial numbers put in by users to make sure it is correct with what is already in database. However, I noticed even if the wrong serial number is inputed, the page reloads (shows the error message) and still fills in the wrong serial number in the field cf_954. So whether it is wrong or right, the field still gets populated.

Firstly, I need to validate the serial numbers put in by users to make sure it is correct with what is already in database. However, I noticed even if the wrong serial number is inputed, the page reloads (shows the error message) and still fills in the wrong serial number in the field cf_954. So whether it is wrong or right, the field still gets populated.

Everything was working fine when running 6.5 until i migrated from 6.5 to 7.0.1.