unable to add fields

hi

I hav modified the standard HTML code for BP Search according to my requirement and hav uploaded.

now when i go to IMG->customer relationship management->IC winclient -> customer-specific system modifications for IC -> define customer specific search control.

here i select the fields needed and click new entries.

it opens <maintainance for search components >

now in HTML BP fiels i m giving zhtml.

table -> table name

field -> field name

add -> x

now problem is at bottom it shows "target key must be different from the source key ".what is it?