How can i display messsage, if i click on Go button, if no data in OVS help

Hi Gurus,

Currently i am working CATS application ESS, here i facing some problem with OVS help.

Here Once click on Task Level or Activity Type F4 help, it is displaying Popup screen with Go and Exit buttons, here once click on Go buttons, if there is no data avaliable in backend, it should display message like "There is no data avaliable".

How can i achieve this, could you please help me on this.

Thanks

Venkat.