[OpenLayers-Users] confused about wms projections and spherical mercator

[Jonathan Wolfe]

Hi,

I'm just playing with the examples here 
(http://trac.openlayers.org/wiki/AvailableWMSServices) and can't get 
this one to plot on a spherical mercator as it gives:

msWMSLoadGetParams(): WMS Server error. Invalid SRS : SRS must be valid 
for all selected layers.

Please correct me if I'm wrong, but can't anything be reprojected onto 
the google projection? It's just a reprojection, right?  Also, is 
mapserver on a remote server? Like in this example, it would be their 
mapserver that would need to be changed to reproject the data?  
Hopefully someone can shed some light on how these pieces fit together.

Thanks,
Jonathan


here is the relevant snippets:
 var options = {
                                projection: new 
OpenLayers.Projection("EPSG:900913"),
                                displayProjection: new 
OpenLayers.Projection("EPSG:4326"),
                                units: "m",
                                maxResolution: 156543.0339,
                                maxExtent: new 
OpenLayers.Bounds(-20037508, -20037508, 20037508, 20037508.34)
                        };
map = new OpenLayers.Map('map', options);

var dm_wms = new OpenLayers.Layer.WMS( "DM Solutions Demo",
                "http://www2.dmsolutions.ca/cgi-bin/mswms_gmap",
                {layers: "bathymetry,land_fn,park,drain_fn,drainage," +
                         "prov_bound,fedlimit,rail,road,popplace",
                 transparent: "true", format: "image/png" });

map.addLayer(dm_wms);