title: send argument of link to another link asp net C#
body: <p>I have a default page with a gridview showing different categories.
  When I enter a category, the name of the category is passed as an argument in the link, like</p>
  
  <pre><code>http://localhost:49442/category.aspx?category=Windows
  </code></pre>
  
  <p>I have a link with  in there for a "New topic". I want to send the "category" parameter further.
  I tried an approach but with no results.</p>
  
  <p>The code is </p>
  
  <pre><code>&lt;a id="topicLink" href="default.aspx"&gt;New Topic&lt;/a&gt;
  </code></pre>
  
  <p>And the code in C# is</p>
  
  <pre><code>string x = Request.QueryString["category"];
  topicLink.Href = "newtopic.aspx?category=" + x; 
  </code></pre>
  
  <blockquote>
    <p>Error: the name topicLink does not exist in this context  </p>
  </blockquote>
  
  <p>How can I do this ?</p>