URL rewriting and web.config

[Shinobi]

I am using ASP.net(c#) for my project. In my my project 2 pages are using URL rewriting method by referring this article

URL Rewriting using Intelligencia UrlRewriter Example 1 - Blog Day Afternoon

from my form i used this code.
Response.Redirect("showdetails/" + a);

in my Web.config

<system.webServer>
    <modules runAllManagedModulesForAllRequests="true">
      <add name="UrlRewriter" type="Intelligencia.UrlRewriter.RewriterHttpModule"/>
    </modules>
    <validation validateIntegratedModeConfiguration="false"/>
  </system.webServer>
  <rewriter>
   <rewrite url="~/showdetails/(.+)" to="~/details.aspx?id=$1" permanent="true"/>
</rewriter>

these are the code i used.
this code rewrite my url like this
example

But i wantto remove that "showdetails" part from url and.
create a valid url like this
example
if i copy paste this link into address bar it must work.
If i remove that string, then other pages(Normal pages ending with extension
like index.aspx) they got error.

can i check extension in web.config.? Or is there is any other way for url rewriting?

Please help me...

[Frinavale]

Have you tried adding rewrite entries for the regular pages as well?
Since you are removing the "showdetails" from the URL, the server still needs to be able to map to the files in the "showdetails" directory...which means you have to map to the files that you want to use.