Creating dependent search helps

Hi all,

I want to assign a search help to a custom field. But the values to be shown in this value help are dependent on another standard field on the screen. So how can I pass this screen field value to the search help?

I have gone through this link, https://wiki.scn.sap.com/wiki/display/Img/Using+Search+Helps but it did not answer my question.

Regards

Krishna