Perform a bit-wise AND operation.
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 Syntax

        GT_And(<nNumber1>,<nNumber2>) --> nResult

 Arguments:

      <nNumber1> and <nNumber2> are two numbers that you whish to
      AND together.

 Returns:

      The result of <nNumeric1> AND <nNumeric2>.

 Description:

      GT_And() can be used for any bit oriented masking operation. GT_And()
      is the functional equivlant of the AND instruction in assembler and
      the & operator in C.

 Examples:

      ? GT_And(131,15)           // Print the value of the top nibble.

 Source: AND.C

 Author:  Dave Pearson