diff --git a/unstructured/idl/read_field.pro b/unstructured/idl/read_field.pro
index 66fce62a6..fa39f2447 100644
--- a/unstructured/idl/read_field.pro
+++ b/unstructured/idl/read_field.pro
@@ -1667,6 +1667,25 @@ function read_field, name, x, y, t, slices=slices, mesh=mesh, $
        symbol = '!3|!8B!D!9P!N!3|!X'
        d = dimensions(/b0, _EXTRA=extra)
 
+   ;===========================================
+   ; toroidal vector potential
+   ;===========================================
+   endif else if(strcmp('toroidal vector potential', name, /fold_case) eq 1) or $
+     (strcmp('ay', name, /fold_case) eq 1) then begin
+
+       psi = read_field('psi',x,y,t,slices=time, mesh=mesh, filename=filename, $
+                        points=pts,rrange=xrange,zrange=yrange, $
+                        linear=linear,complex=complex,phi=phi0)
+
+       if(itor eq 1) then begin
+           r = radius_matrix(x,y,t)
+       endif else r = 1.
+   
+       data = psi/r
+       symbol = '!8A!D!9P!N!X'
+       d = dimensions(/b0, /l0, _EXTRA=extra)
+
+
    ;===========================================
    ; Pitch Angle
    ;===========================================