I'm using build 377m. The help for the xsl:choose block says:
Right click on the xsl:choose instruction block.
Select Properties from the shortcut menu.
When I right click on the block, I don't see a Properties selection. What does show up are Delete, Go To Source, Add When to Port.
we don't have property dialog any more. the doc will be updated.
the reason that we dropped the propery dialog is that the choose operation is actually easier to do through block and port. if you want to add a xsl:when branch, you right click on choose block and select "Add When Port". if you want to edit a particular xsl:when condition, you can double click on the port and edit in the editbox.