Scrollbar in a window

[jwmount]

I need a vertical scrollbar in a window I populate via replication. When I put a tag into the window the effect is the window takes a long time to show and when it appears the browser (Firefox) complains about a slow running process slowing everything down.... and there's no scrollbar anyway. Code looks more or less like this:

<window....
<scrollbar/>
<text datapath='...../text()' resize='true'/>
</window>

The window once populated has several hundred lines in it so I need to give the user some way to navigate it beyond dragging it around.

Thanks!