In this paper, we demonstrate by simulation the feasibility of electrostatically doped and therefore reconfigurable planar field-effect-transistor structure which is based on our already fabricated and published Si-nanowire devices. The technological cornerstones for this dual-gated general purpose FET contain Schottky S/D junctions on a silicon-on-insulator substrate. The transistor type, i.e. n-type or p-type FET, is electrically selectable on the fly by applying an appropriate control-gate voltage which significantly increases the versatility and flexibility in the design of digital integrated circuits.