How to by-pass a recorded screen in lsmw, if the field in it is initial?

Hi

I am doing recording for AS02 ttransaction.

In this (AS02) transaction,we have Time dependent tab.And I am recording all fields in that tab .And then go to other screen by pressing 'Add interval ' button and will update the only field date(ANLZ-ADATU) there for recording purpose.

Here there are two points to be noted.

1.While updating the text file (where we store data to update) ,if ANLZ-ADATU (date) is initial no need to go and update date i.e no need to go to that screen ,just skip that screen .

2.If ANLZ-ADATU is not initial ,it will go to other screen and do update process.

Here where should I add the condition to skip the 'update date' screen and process to next row of data in the file?