How can I read text from cache into user name field of ASP.NET login control

Question

I have a primary ASP.NET site that asks for a user name.

When the user gives a user name and clicks the submit button, he/she is redirected to the respective application (actual site) based on their user name (user name goes into cache here). User names across all sites are unique.

I want to use the cache to read back the user name entered in step 1 into the user name field of ASP.NET login control where user actually logs into the application (site). All the sites are on the same server and use the same domain. eg: site1.domain.com, site2.domain.com.

Answer 1

If it's just the username, why not use the querystring i.e. redirect to login.aspx?username=USERNAME?