If you need to select all horizontal or vertical lines within a drawing, this could be a tedious work. It is not easy to
select them in quite a complex drawing. But you can do it easily if you use QSELECT tool.

So how to use it to select all vertical lines? Simple. It means they have the same X value, and horizontal lines
have the same Y value. When you activate quick properties window, change object type to line, properties to
Delta X (or Delta Y), change the value to 0. Click OK, you are done!

Remember: You can filter the selection further. You can choose only vertical lines on layer 1, or horizontal lines
that have red color, with a specific length, and so on.