A preferred set of prices for a plurality of products, generally demand coefficients is provided. The CPU enables input by the first touch sensor when the second cabinet is in a first position or OP position where the second case exposes a detection area of the first touch sensor to the outside, and disables input by the first touch sensor when the second cabinet is out of the first position. At least one pair of vertically extending support members have a pincher or pincher mechanism that squeezes upon one of the vertically extending support members to fix the vertically extending support members in a nonsliding fashion relative to each other. A conductive material layer having slant exterior sidewalls is formed over the dielectric layer. Such grip locking may be employed throughout tractoring or intermittently, depending upon well characteristics such as formation hardness and well diameter. A second electrode is formed over the second impurity semiconductor layer.