How to: Use Breakpoints with XSLT
You can set breakpoints in an XSLT style sheet. Breakpoints can be set on all start tags, end tags and on text nodes. If you set a breakpoint on a tag that does not have corresponding source line information, when execution is started the breakpoint jumps to the next statement that has source line information.
Breakpoints have to be anchored. That is, if a valid breakpoint is set on line 10 and you go to line 9 and add 4 extra blank lines, the break point moves to line 14.
For more information, see Debugging Basics: Breakpoints.
To set a breakpoint
Open the style sheet in the XML Editor.
Position the cursor at the breakpoint location, right-click, point to Breakpoint, and click Insert Breakpoint.