1. Open IIS Manager
2. Browse to you web site.
3. Open the "URL Rewrite" feature.
4. In the Actions pane, click "Add Rules..."
5. In the "Add rule(s)" dialog select the template "User friendly URL" and click OK.
6. In the opened dialog, enter the internal URL that you expect, that is "/request.asp?city=austin"
7. In the combo box select the public URL that suits you, that would be "/request/austin/"
8. A small change once you select the combo item, in the URL pattern text box change "^request/([^/]+)/?$" by "^tree-service/([^/]+)/?$"
9. Click OK and you should be ready to go.