FAILAT [failat_level]

* FAILAT sets the error code level at which scripts (and multiple
  commands on one line) will be aborted. The default level is 10.
  Most commands return 10 as an error, (20 for serious errors)
  while compilers returning Warning type errors will return 5.
  Hence, the default of 10 will allow Warnings to occur without
  the script (or line) being aborted. If a command returned an error
  code higher than the failat level, it will be printed out on the
  window.

eg.     failat 20       {sets failat level to 20}

* If you do not specify a failat level, the current setting is
  shown.

eg.     failat