Can you explain why you are trying to get pre-defined x/y values? Are you trying to get the x/y values of the extent when the map resource loads? Or are you trying to get the coordinates for some other location? Generally, when you add a layer (ArcGISTiledMapServiceLayer, ArcGISDynamicMapServiceLayer, etc) to your map object, the map's extent object automatically inherits the extent defined in your Map Service Layer. You can get the x/y values from this object by querying the map.extent x/y attributes (http://help.arcgis.com/EN/webapi/javascript/arcgis/help/jsapi_start.htm extent is under the geometry category on the right hand side). You can also create an extent object and set its x/y values to the extent of another geometry object, such as a polygon. In general, you shouldn't have to change the spatial reference unless you are dealing with data in mulitple spatial references.
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