FUNCTION Count_Rows, filename, MaxRows = maxrows

; This utility routine is used to count the number of
; rows in an ASCII data file.

IF N_Elements(maxrows) EQ 0 THEN maxrows = 500

OpenR, lun, filename, /Get_Lun

Catch, error
IF error NE 0 THEN BEGIN
   count = count-1
   RETURN, count
ENDIF

count = 1
line = ''
FOR j=count, maxrows DO BEGIN
   ReadF, lun, line
   count = count + 1
ENDFOR

RETURN, -1
END