Geotag – Multiple markers

Anybody know how to display multiple markers on the map ie:

1. marker_lat=’56.797055′ marker_lon=’-5.003879′
2. marker_lat=’54.447345′ marker_lon=’-3.243894′
3. marker_lat=’53.068067′ marker_lon=’-4.077588′

At the moment I can only get it to display the last one:

[gmap file=’http:***’ marker_lat=’56.797055′ marker_lon=’-5.003879′ marker_lat=’54.447345′ marker_lon=’-3.243894′ marker_lat=’53.068067′ marker_lon=’-4.077588′]

Cheers,

Martin