DataSource Controls :: Setting A Typed DataSet (xsd) Connectionstring Dynamically?

I'm trying to set up a simple content management system for two different sites, which are both stored on the same server (my own, not hosting, if it matters:)).

Both sites are basically the same, built upon a similar (but seperate) xsd (Typed DataSet) file, and read data from different databases using the tableadapters in the xsds.

Obviously, i have the same xsd setup in my management system application that need to hook up to the relevant database (after user authentication) and use the tableadapters to access the data and allow the forms in the management system to modify the data.

When i had a single site, the connection string was stored in the web.config file and after logging in to the management system, all forms could access the database.

Now i have two site and i need to setup the connection string in the xsd dynamically after user validation based on the relevant site to edit.

My question is, how do i set the xsd's connection string dynamically (after user logs in, the function returns the specific connectionstring and stores it in a Session variable)