You can use Project variable as your identification property. So you can set your URL whatever you want for different environments.
For this, Instead of constants you should select project variable in Edit identification properties.
This needs to be set before you access the particular object.
All ideas presented are very good ideas, depending upon what you want to do. That's, again, one of the bonuses of using NameMapping in that you can map something like your main page URL to be dynamically determined either using a wildcard, a project variable, using a conditional mapping, etc. Anyone of those ways would allow you to test, regardless of environment, without having to change your Alias... a simple commandline switch or, as mentioned, INI configuration could trigger the use of a different environment and then the Alias could account for it.
