Redirect page based on query string parameter?

I am trying but open in next window
I  am clicking selecting in default page ,second page url like this http://localhost:3951/query/QueryStringParams2.Aspx?TagId=1
Based on that TagId query string value will open In the browser in the same window(Ex:www.asp.net)
After that URL same http://localhost:3951/query/QueryStringParams2.Aspx?TagId=1,I want to chnge TagId=2 based on that TagId value open in the same page(EX:www.bing.com) and so on
Table like this in database
TagId NAME coupounurl
1       asp      www.asp.net
2      weblog  www.bing.com
3      google   www.google.com
Default.aspx
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> ...