PAI validation

Hi Group,

When I am validating one field(for Mandatory check) in one of my transactions using chain and End chain with throwing error message,its working fine hwne I entered and also when I go for first time save in that tab(by throwing Error),when I go to some other tab( in the same transaction) and I click save it is allowing to save and the data in that particular tab (where Validation check working) erased.

Can any body suggest how to solve this