[OpenLayers-Users] Dynamically updated markers

[PPaFin]

I've been trying to implement dynamically updated markers with 
openlayers, but this subject is difficult to cover.

My plans includes ajax scripting, where I manage to do periodical 
execution of function. In that function my plans would include following 
layer firing:

newl = new OpenLayers.Layer.Text( "Realtime data", {location: 
"textfile2.txt", projection: new OpenLayers.Projection("EPSG:4326") } );

(Where I would replace textfile2.txt with PHP script, which reads values 
from database and produces correctly formated output).

But how do I refresh marker layer to reflect (and refresh) periodically 
generated (new) state of marker locations?

I've tried: map.addLayer(newl); and map.redraw(newl); with no success.

All I managed to do so far, is 'at start' initiated drawing of markers, 
but further refreshing of those markers and their position have been 
problem.

Any idea ?

Regards,

Pasi