.ERRB            Error If String Is Blank                      MASM Directive

  .ERRB     <string>

    Forces a fatal error if string is blank.

       Notes:     Note that the angle brackets, <>, are required around
                  the string.  The string can be any name, number, or
                  expression.

                  The error message that may be generated by this
                  directive is 'Forced error - string blank', which is
                  error number 94.

                  If an error is generated, then the object module is
                  deleted and the assembler exits with an exit code of 7.

                  .ERRB and .ERRNB are usually used to detect the presence
                  or absence of parameters in a macro.