PRO TEST_BREAK, ARR, X

n = n_elements(arr)
i = 0L
while (i lt n) do begin
  if (long(arr[i]) eq long(x)) then break
  i = i + 1L
endwhile

if (i lt n) then begin
  print, 'Matching value found at element ', i
endif else begin
  print, 'No matching values were found'
endelse

END