DXF line type

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X-Sun-Data-Type: text
X-Sun-Data-Description: text
X-Sun-Data-Name: text
X-Sun-Content-Lines: 14

To all users of grass and autocad
For my project I got data in DXF format, I imported the data with the help of v.in.dxf and everything was fine.
Except for one thing. I want to create areas of a certain layer, but the lines in this layer aren't closed , they look something like ----- . . . ------
While I don't have a copy of autocad my question is as follows
Is there a possibility of changing the line type in the DXF file and if there is what is the typenumber or code for a closed line. Where in the DXF file is the line type defined.
Thanks for any advise

***********************************************
* Ronnie Lassche *
* Department of earth sciences *
* Free University *
* Amsterdam *
* lasm@geo.vu.nl *
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X-Sun-Data-Type: default
X-Sun-Data-Description: default
X-Sun-Data-Name: handtekening
X-Sun-Content-Lines: 7

***********************************************
* Ronnie Lassche *
* Department of earth sciences *
* Free University *
* Amsterdam *
* lasm@geo.vu.nl *
***********************************************