We present results from a Monte Carlo study of functional polymers at a solid-liquid interface, when both the "anchors" and the "backbones" of the polymer chains adsorb to the interface, but with unequal strengths. We have studied the configuration of the polymer chains as the surface density of the anchors is increased. For small values of the anchor density, both the anchors and the backbones reside close to the interface, and thus the adsorbed polymer layer takes a so-called "pancake" shape. As the surface density of the anchors is increased, the anchors replace more and more backbone monomers on the interface and as a result the layer becomes more extended, like a grafted polymer brush. Data for density profiles and layer thickness support this picture. We find that the pancake to brush behavior becomes sharper as the chain length is increased.