Use ArcCatalog to see exactly what you have to use for the visiblelayers Ids. Using the url you provided: http://webservices.nationalatlas.gov/wms/transportation? I added it as a WMS Server and then double clicked on the lay I wanted to get the name for and this is what I see: [ATTACH=CONFIG]22748[/ATTACH]
Don't forget to click the Mark as answer check on this post and to click the top arrow (promote). Follow these steps as shown in the below graphic:
Use ArcCatalog to see exactly what you have to use for the visiblelayers Ids. Using the url you provided: http://webservices.nationalatlas.gov/wms/transportation? I added it as a WMS Server and then double clicked on the lay I wanted to get the name for and this is what I see: [ATTACH=CONFIG]22748[/ATTACH]
Don't forget to click the Mark as answer check on this post and to click the top arrow (promote). Follow these steps as shown in the below graphic: