The JavaScript code below generates a a single-element data array and stores the result into a clip property.
var oStrings =
[
"PG3032901074056",
"PG3052321074056",
"PG3062641074056",
"PG3082651074056",
"PG3182821075056",
];
// choose element from array based on a random number
var a = oStrings[Math.floor(oStrings.length * (Math.random()))];
// set clip property to contents of “a” – the randomly selected index value
$prop.set("MessageClip", "Ecard", a);
// show debug information in results
$context.result.postMessage($context.result.LEVEL_INFO, "Ecard: " + a);