join curves

 From:  eric (ERICCLOUGH)
8785.1 
Hi ..
Now and then I create a flat surface (or hope to) by offsetting lines (or copying) and then drawing lines between the ends and using 'join' to connect. Then I use the 'planar' command to create the surface ... but there are times when that does not happen. I can't see that the curves are not planar or properly joined.
When this happens I open the drawing in Rhino and use 'closecrv' command which reports that a segment has been added.
Then back to MoI and the planar command creates the surface.
Is there a way to do this without going to Rhino for the fix?
Thanks,
eric