LValue

Description:              Left-hand Side Value.  This function returns an indication of whether its argument can be used on the left-hand side of an assignment.

Returns:                    Boolean

Usage:                       Script or Steady State

Format:                      LValue(Expr)

Parameters:             Expr    { text }  { required }  { no default }

                                      Any expression.

Comments:               This is a compiler function that returns 1 (true) if data can be stored into Expr (i.e. if it is a variable, etc.) and 0 otherwise.