You can set the default a couple of different ways:
Use the selectedIndex property:
$w("#myDropdown").selectedIndex = 0; // select first option as default
Use the value property:
$w("#myElement").value = "red"; // choose the color red as default
You can set the default a couple of different ways:
Use the selectedIndex property:
$w("#myDropdown").selectedIndex = 0; // select first option as default
Use the value property:
$w("#myElement").value = "red"; // choose the color red as default