Set Accordion Panel as Default?

How do you set one accordion panel as the default? Each time someone opens the form, I want the first panel to be open by default. How would I do that?

Dear Maura,
While it’s possible to set default panel in the designer, the browser will also cache the last opened panel, so it won’t be always the first panel that opens when you open the form. To rectify this, you can use the following JavaScript inside of JS editor:

fd.spRendered(function() {
    var accordion = fd.container('Accordion0');
    //opens panel if it is closed
    if (accordion.$children[0].open == false){
        accordion.$children[0].toggle();
    }
});