diff --git a/src/idl/dustem_habing_field.pro b/src/idl/dustem_habing_field.pro
index 00543b8..77feff3 100644
--- a/src/idl/dustem_habing_field.pro
+++ b/src/idl/dustem_habing_field.pro
@@ -1,4 +1,65 @@
 FUNCTION DUSTEM_HABING_FIELD, x, unit=unit
+
+;+
+; NAME:
+;   dustem_habing_field
+;  
+; PURPOSE:
+;   Returns the Habing interstellar radiation field SED (ISRF)
+;   in W/m2 (4*!pi*nu*I_nu)
+;   (from Draine & Bertoldi 1996)
+;
+; CATEGORY:
+;    DustEMWrap, Distributed, LowLevel, Helper
+;  
+; CALLING SEQUENCE:
+;   habing = DUSTEM_HABING_FIELD(x,unit=unit)
+;
+; INPUTS:
+;    x : wavelength grid for the ISRF (1D array)
+;
+; OPTIONAL INPUT PARAMETERS:
+;    UNIT: unit of the ISRF. Choices are 
+;	     'W': wave in um [Default]
+;	     'F': frequency in cm-1
+;	     'E': energy in eV
+;
+; OUTPUTS:
+;    ISRF : the Habing isrf as 1d vector in requested units
+;
+; OPTIONAL OUTPUT PARAMETERS:
+;
+; ACCEPTED KEY-WORDS:
+;    help = print this help
+;
+; COMMON BLOCKS:
+;    None
+;
+; SIDE EFFECTS:
+;
+; RESTRICTIONS:
+;
+; PROCEDURES AND SUBROUTINES USED:
+;   
+; EXAMPLES
+;      wavs=3.+findgen(3000) ; wavelenghts 3 to 3003um
+;      isrf = DUSTEM_HABING_FIELD(wavs,unit='W')
+;
+; MODIFICATION HISTORY:
+;    Written by LV 2009
+;    Initially distributed with the Fortran, incorporated into DustEMWrap 2022
+;    Evolution details on the DustEMWrap gitlab.
+;    See http://dustemwrap.irap.omp.eu/ for FAQ and help.  
+;-
+
+  IF keyword_set(help) THEN BEGIN
+     doc_library,'dustem_habing_field'
+     field=0
+     goto,the_end
+  ENDIF
+
+
+
 ; computes the Habing interstellar radiation field SED (ISRF)
 ; in W/m2 (4*!pi*nu*I_nu)
 ; (from Draine & Bertoldi 1996)
@@ -29,5 +90,6 @@ FUNCTION DUSTEM_HABING_FIELD, x, unit=unit
  i_neg = where( field LT 0.d0, c_neg )
  field( i_neg ) = 0.d0
 
+ the_end:
  RETURN, field
 END                             ;FUNCTION DUSTEM_HABING_FIELD
diff --git a/src/idl/dustem_mathis_field.pro b/src/idl/dustem_mathis_field.pro
index b488d0f..a6ea16d 100644
--- a/src/idl/dustem_mathis_field.pro
+++ b/src/idl/dustem_mathis_field.pro
@@ -1,12 +1,61 @@
-FUNCTION DUSTEM_MATHIS_FIELD, x, unit=unit
-; computes the Mathis interstellar radiation field SED (ISRF)
-; in W/m2 (4*!pi*nu*I_nu)
+FUNCTION DUSTEM_MATHIS_FIELD, x, unit=unit, help=help
+
+;+
+; NAME:
+;   dustem_mathis_field
+;  
+; PURPOSE:
+; Returns the Mathis interstellar radiation field SED (ISRF) in W/m2 (4*!pi*nu*I_nu)
 ; from Mathis et al. 1983, A&A 128, 212
-; X	(I): X-grid for the ISRF
-; UNIT	(I): unit of the ISRF. Choices are 
+;  
+; CATEGORY:
+;    DustEMWrap, Distributed, LowLevel, Helper
+;  
+; CALLING SEQUENCE:
+;   mathis = DUSTEM_MATHIS_FIELD(x,unit=unit)
+;
+; INPUTS:
+;    x : wavelength grid for the ISRF (1D array)
+;
+; OPTIONAL INPUT PARAMETERS:
+;    UNIT: unit of the ISRF. Choices are 
 ;	     'W': wave in um [Default]
 ;	     'F': frequency in cm-1
 ;	     'E': energy in eV
+;
+; OUTPUTS:
+;    ISRF : the Mathis isrf as 1d vector in requested units
+;
+; OPTIONAL OUTPUT PARAMETERS:
+;
+; ACCEPTED KEY-WORDS:
+;    help = print this help
+;
+; COMMON BLOCKS:
+;    None
+;
+; SIDE EFFECTS:
+;
+; RESTRICTIONS:
+;
+; PROCEDURES AND SUBROUTINES USED:
+;   
+; EXAMPLES
+;      wavs=3.+findgen(3000) ; wavelenghts 3 to 3003um
+;      isrf = DUSTEM_MATHIS_FIELD(wavs,unit='W')
+;
+; MODIFICATION HISTORY:
+;    Written by LV 2009
+;    Initially distributed with the Fortran, incorporated into DustEMWrap 2022
+;    Evolution details on the DustEMWrap gitlab.
+;    See http://dustemwrap.irap.omp.eu/ for FAQ and help.  
+;-
+
+  IF keyword_set(help) THEN BEGIN
+     doc_library,'dustem_mathis_field'
+     field=0
+     goto,the_end
+  ENDIF
 
  if n_elements( UNIT ) EQ 0 then unit = 'W' $
  else unit = strupcase( strcompress( unit,/rem) )
@@ -47,6 +96,6 @@ FUNCTION DUSTEM_MATHIS_FIELD, x, unit=unit
  il = where( x3 GE 1.34 AND x3 LT 2.46, cl )
  if cl GT 0 then field(il) = 3.3105d-6 * x3(il)^(-0.6678)
   
-
+the_end:
  RETURN, field
 END                             ;FUNCTION DUSTEM_MATHIS_FIELD
--
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