| pDC | A pointer to a device context. | 
    | pSlider | A pointer to a slider. | 
    | rect | Bounding rectangle. | 
    | bIsHighlighted | TRUE if the thumb is highlighted. | 
    | bIsPressed | TRUE if the thumb is pressed. | 
    | bIsDisabled | TRUE if the thumb is disabled. | 
    | bVert | Specifies whether the slider is vertical (TRUE), or horizontal (FALSE). | 
    | bLeftTop | Specifies the thumb orientation. If TRUE, the thumb's arrow points to the left or up (depending on bVert). If FALSE, the thumb's arrow points to the right or bottom. | 
    | bRightBottom | Specifies the thumb orientation. If TRUE, the thumb's arrow points to the right or bottom (depending on bVert). If FALSE, the thumb's arrow points to the left or top. | 
    | bDrawOnGlass | If TRUE, the thumb is drawn on the glass (Vista Aero only). |