WINSETGAUGE expression , expression , expression

   Synopsis:
      Updates a task window gauge

   Notes:
      Updates a gauge that was added to the task window with a WINADDGAUGE or
         WINADDCONGAUGE statement.
      The first expression is the gauge's unique number. If the gauge doesn't
         exist, the WINSETGAUGE statement is ignored, but the number isn't an
         integer, 0 or above, you'll see an error message.
      The second and third expressions should evaluate to numbers used to set
         the length of the "full" and "empty" portions of the gauge. Any decimal
         number is acceptable, even negative numbers. If these expressions don't
         evaluate to a number, the gauge is blanked.
      After a WINADDGAUGE statement, the first number is expected (but not
         required) to be less than or equal to the second one. After an
         WINADDCONGAUGE statement, the sum of the two numbers is expected (but
         not required) to be constant, at least in the short term.

   Requires:
      If the script is not being run as a task, the SETGAUGE statement is
         ignored (and no error message is generated). Execution continues with
         the next statement.

   Examples:
      ! Character's health points are at 50%
      WINADDGAUGE 1, "HP", "RED", "red", "WHITE"
      WINSETGAUGE 1, 50, 100

      ! Character's energy points are very low
      WINADDGAUGE 2, "EP", "GREEN", "green", "black"
      WINSETGAUGE 2, 0.017, 1

      ! Show a gauge where the two numbers are added
      ! Character has 900xp, and needs 100 more to level up
      WINADDCONGAUGE 3, "XP", "MAGENTA", "magenta", "WHITE"
      WINSETGAUGE 3, 900, 100
