pro refline,x,y,value,linetype

;The procedure refline.pro puts a reference line on a plot.
;Use is as follows:
;          refline,x,y,value,linetype
;Where 
;                  x = 1 to put a vertical line(s), =0 otherwise
;                  y = 1 to put a horizontal line(s), =0 otherwise
;              value = a number or array of numbers that gives the
;                      axis values for the lines desired
;           linetype = a number denoting the linestyle
;                      (0-solid, 1-dotted, 2-dashed, 3-dash dot
;                       4-dash dot dot dot, 5-long dashes)
;BWBerger Summer 1998.
;Modified by BWB 1/12/99 to hopefully fix a problem where the lines
;would not be drawn for some axes ranges. -The fix was hopefully the
;use of a 100 points, evenly spaced at each value, instead of just endpoints. 

val=fltarr(len(value),100)
for i=0,len(value)-1 do begin
   val(i,*)=float(value(i))
endfor

val2=(findgen(100)-50)*10000.

for i=0,len(value)-1 do begin
  if x eq 1 then begin
    oplot,val(i,*),val2,$
          linestyle=linetype
  endif

  if y eq 1 then begin
    oplot,val2,val(i,*),$
          linestyle=linetype
  endif
endfor

return
end