BLANK()
 Creates a blank value for each data type
------------------------------------------------------------------------------
 Syntax

     BLANK([<expValue>], [<lMode>]) --> xBlank

 Arguments

     <expValue>[@]  Designates any valid expression; the type is not
     important.

     <lMode>  Designates whether or not the length of the <expValue> is
     to change in the event that <expValue> is a string.  If .T. is
     designated, the length is retained.  The default value is Change Length
     (.F.).

 Returns

     BLANK() returns a blank value with the same data type as the <expValue>
     parameter.

 Description

     BLANK() clears desired data fields with the variables.  BLANK() returns
     the following results:

     Table 13-1: Data Type Blank Values
     ------------------------------------------------------------------------
     Argument            Returned Value
     ------------------------------------------------------------------------
     Character string    Null string or blank string
     Numeric             Value of 0
     Logical             .F.
     Date                A blank date
     ------------------------------------------------------------------------

     The default for <lMode> is .F. and produces a null string when a
     character string is input.  However, if this parameter is designated as
     .T.., the string length is not changed.

 Notes

     .  SET DATE has no affect on how BLANK() handles a date.  The
        blank date display is created in the format you select.

     .  You can suppress the value this function returns by
        manipulating strings through CSETREF() implementation.  To save room
        in the working memory, designate <lMode> as .T..

 Example

     Display blank values for data-type values:

     SET DATE AMERICAN
     ? BLANK(DATE())          // "  /  /  "
     ? BLANK()                // .F.
     ? BLANK(.T.)             // .F.
     ? BLANK(99)              //  0
     ? BLANK("abc")           // ""
     ? BLANK("11:59:59")      // ""
     ? BLANK("abc", .T.)      // "  " Blank string