OSM Map projection doesn't seem to change

Question

I have the following OpenLayers map:

Proj4js.defs["EPSG:31258"] = "+proj=tmerc +lat_0=0 +lon_0=13.33333333333333 +k=1 +x_0=450000 +y_0=-5000000 +ellps=bessel +towgs84=577.326,90.129,463.919,5.137,1.474,5.297,2.4232 +units=m +no_defs";
var googleProj = new OpenLayers.Projection("EPSG:900913");
var salzburgProj = new OpenLayers.Projection("EPSG:31258");
var bounds = new OpenLayers.Bounds(426249,294999,426251,295001);
var maxZoom = 19;
var minZoom = 15;
var res = [4.77731426696777,2.38865713348389,1.194328566741945,0.5971642833709725];

mapCOD = new OpenLayers.Map({
    div: "mapCODs",
    allOverlays: true,
    maxExtent: bounds,
    projection: salzburgProj,
    allowSelection: true,
    controls: [new OpenLayers.Control.PanZoomBar(), new OpenLayers.Control.Navigation()]
});

var layer = new OpenLayers.Layer.OSM(
        "layer1",
        "tiles/input/${z}/${x}/${y}.png",
        {zoomLevels: maxZoom, zoomOffset: minZoom, resolutions: res}
    );          
mapCOD.addLayer(layer);

I have produced tiles with mapnik using EPSG:31258, so I would like to change the default projection of the map from 900913 to 31258. The problem is that "projection" parameter is not taken into account and if I perform a console.log(mapCOD.getProjection()), I obtain "EPSG:900913".

Another proof that map projection remains 900913 is that I have to perform a coversion to get the correct map center:

var center = bounds.getCenterLonLat();
mapCOD.setCenter(center.transform(salzburgProj,googleProj), minZoom);

What am I missing?

Answer 1

try this:

map.projection = new OpenLayers.Projection("EPSG:31258");
map.displayProjection = new OpenLayers.Projection("EPSG:4326");

or write like this:

mapCOD = new OpenLayers.Map('map', {           
    numZoomLevels: 20,
    projection: new OpenLayers.Projection("EPSG:31258"),
    displayProjection: new OpenLayers.Projection("EPSG: 4326")
});

i hope it helps you....