Delete a bezier line

[jim cubie]

I created the simple diagram attached with the bezier pen.  I now want to delete the long horizontal line at the top.

I have converted the strokes to paths.

When I select both nodes try to delete the line by clicking the "delete segment between 2 nodes" tool nothing happens.

When I select the 2 nodes and hit the delete key most of the diagram turns black.

I notice that there are actually 2 nodes on each corner.   If I "join Selected Nodes" on each corner and then select the line by selecting both nodes, the horizontal line is deleted but part of the vertical lines that were connected to the deleted horizontal line get narrower and shorter.

I have done a lot of googling to no avail.  Appreciate your help.  HOw do I delete the long horizontal line at the top of the diagram?

[Lazur]

It's that the stroke was converted to path, therefore the "side" is not one segment but two.
By adding a stroke to the object it can stick out more.
Just connect unconnected nodes at both "ends" and it will look as expected.

[jim cubie]

I just don't get it.   By "connect the nodes" what do you mean?  Do you mean that I should select the nodes at the corner using "join selected nodes?"  I have done that on both corners and then selected both corners and clicked on "delete segment between 2 non-end points" and it did not delete.

Very frustrated.  There is something about nodes that I do not understand.  Please call me at 843-991-1059.  I simply want to delete  that line. 

[Lazur]

I mean that since you converted the strokes to path it's no longer one segment.
Rather, now the previous visual area of the stroke is built up from a path with two sides.
You unconnected four nodes at the top.
If you add a stroke and no fill to the path you can see that now on both of the previous segments ends are unconnected.
The black fill used in your open path now renders as a bubble membrane, filling up the space in between.