Setting repeater row to selected on page load




I have a “simple” question I can’t seem to work out/find an answer to. Quite new with Axure…

I have a repeater on a page with a list of selectable items.
Depending on what is selected another dynamic panel change content.

I would like to have the top repeater item pre-selected on page load (and the corresponding panel change) but I can’t find anywhere to select a row on load.

Can anyone point me in the right direction?