Validations on the screen.

Hi,

I have one field in the screen that screen I have designed using screen painter. If I enter some thing in that filed first I am checking one condition like whether that is exists in table or not if not I am giving error message. It is displaying error message but it is not allowing to enter any thing on that field I mean it is showing in grey color but I want in input allow mode. Please help me where I need to put the logic and what logic I need to put for that. And one more doubt is in the another screen I am entering value in the net weight (vekp-ntgew) field but I need to validate that field in the following way

If any body enters value like 100.532 system should display error message and it can allow to enter another value in the same screen. Please help me how to resolve above problems.

Thanks a lot.