Mine

function showTrailOnMap(reg)
			{				
				tlFirst.destroyFeatures();
				tlSecond.destroyFeatures();
				tlThird.destroyFeatures();
				tlFourth.destroyFeatures();
				
				
				var firstURL = '/beacon.php?type=geoJson&action=findTrail&registration='+reg+'&hours=0&offset=6';
				var secondURL = '/beacon.php?type=geoJson&action=findTrail&registration='+reg+'&hours=6&offset=12';
				var thirdURL = '/beacon.php?type=geoJson&action=findTrail&registration='+reg+'&hours=12&offset=18';
				var fourthURL = '/beacon.php?type=geoJson&action=findTrail&registration='+reg+'&hours=18&offset=24';
				
				
				
				var format = new OpenLayers.Format.GeoJSON({
                    'internalProjection': new OpenLayers.Projection("EPSG:900913"),
                    'externalProjection': new OpenLayers.Projection("EPSG:4326")
                });
				
				// Get the first most recent 6 hour trail
				OpenLayers.loadURL(firstURL, {}, null, function (response){
					var geoJSON = response.responseText;
					var features = format.read(geoJSON);
					tlFirst.addFeatures(features);
				});

				// Get the second most recent 6 hour trail
				OpenLayers.loadURL(secondURL, {}, null, function (response){
					var geoJSON = response.responseText;
					var features = format.read(geoJSON);
					tlSecond.addFeatures(features);
				});
				
				// Get the third most recent 6 hour trail
				OpenLayers.loadURL(thirdURL, {}, null, function (response){
					var geoJSON = response.responseText;
					var features = format.read(geoJSON);
					tlThird.addFeatures(features);
				});
				
				// Get the fourth most recent 6 hour trail
				OpenLayers.loadURL(fourthURL, {}, null, function (response){
					var geoJSON = response.responseText;
					var features = format.read(geoJSON);
					tlFourth.addFeatures(features);
				});
				
			}