Beginner ASP.net question handling url link
<p>I want to handle links like this:</p>

<pre><code>http://example.com/test.aspx?userid=tras&amp;server=bum
</code></pre>

<p>I looked <a href="http://www.15seconds.com/Issue/020417.htm" rel="nofollow">here</a>, and they do this:</p>

<pre><code>HttpApplication objApp = (HttpApplication) sender;  &lt;--- ERROR LINE
string userid = objApp.Request["userid"].ToString();
</code></pre>

<p>But I get the error:</p>

<pre><code>Unable to cast object of type 'ASP.test_aspx' to type 'System.Web.HttpApplication'.
</code></pre>

<p>I need simple input from html nothing fancy. Just to get couple of string items in way described above,</p>
