navigation on aspx page with sql

Question

I've inherited an .aspx site and have to have it up and running in 2 weeks. The default page has an asp menu across the top. First link pulls another aspx page into a content place holder. The page pulled in has a drop-down and user selects a value from a sql table - rest of the page is populated based on selection. 

 

The other links go out to various other aspx pages and external sites. 

 

My question is does anyone have suggestions, to retain their selection and population on that first page when they select other menu options and then return to that first link?