Hi Rurangwa,
EmpId is a "strange beast"... and one of the reason for which I'm always looking first at what is doing SAP in its forms (catches the FORM_OPEN event of the corresponding system form, then saves its xml definition) when I'm asked to have a similar functionality in my own forms.
In this specific case, they are two EditText objects, one above the other (same size and coordinates, z-order (order of creation) displays the name and not the Id) and the LinkButton is linked... to the underneath Edit, not the visible one.
Regards,
Eric