In Webtrends, events that happens after the page loads can be tracked using dcsMultiTrack.

This takes the following form:
[source]dcsMultiTrack( key1, value1, key2, value2, key3, value3, ... );[/source]

But what if you don't know how many key/value pairs you'll be sending into dcsMultiTrack? How do you call it then?

Take advantage of the JavaScript apply function. Create an array of key/value pairs and then apply that array to the dcsMultiTrack function:

[source]
var webtrendsArgs = [
'DCSext.w_event_type', 'Video Started',
'DCSext.w_video_id', 'xxxx-yyyy-zzzz-1234',
'DCSext.w_video_name', 'Kitten Video'
];

dcsMultiTrack.apply(this, webtrendsArgs);
[/source]

This is equivalent to:

[source]
dcsMultiTrack(
'DCSext.w_event_type', 'Video Started',
'DCSext.w_video_id', 'xxxx-yyyy-zzzz-1234',
'DCSext.w_video_name', 'Kitten Video'
);
[/source]

If needed, you can add the key/value pairs to webtrendsArgs array incrementally and when complete, apply this to dcsMultiTrack at the end.

Source: StackOverflow