How to rewrite a URL?

public class FormRewriterControlAdapter : System.Web.UI.Adapters.ControlAdapter
{
    protected override void Render(System.Web.UI.HtmlTextWriter writer)
    {
        base.Render(new RewriteFormHtmlTextWriter(writer));
    }
}
public class RewriteFormHtmlTextWriter : HtmlTextWriter
{
    public RewriteFormHtmlTextWriter(HtmlTextWriter writer)
        : base(writer)
    {
        this.InnerWriter = writer.InnerWriter;
    }
    public override void WriteAttribute(string name, string value, bool fEncode)
    {
        if (name == "action")
        {
            HttpContext Context;
            Context = HttpContext.Current;
            if (Context.Items["ActionAlreadyWritten"] == null)
            {
                value = Context.Request.RawUrl;
                Context.Items["ActionAlreadyWritten"] = true;
            }
        }
        base.WriteAttribute(name, value, fEncode);
    }
}

<rewriter>
<rewrite url="/WebSite3/Product/(.+)" to="/WebSite3/Product.aspx?category=$1" />
<!--<rewrite url="/WebSite3/Product/(.+).aspx" to="/WebSite3/Product.aspx?category=$1"/>-->
<!--<rewrite url="/WebSite3/Product/books.aspx" to="/WebSite3/Product.aspx?category=books" />-->
</rewriter>

<browsers>
   <browser refid="Default">
      <controladapters>
         <adapter controltype="System.Web.UI.HtmlControls.HtmlForm">
	   adapterType="FormRewriterControlAdapter" />
         </adapter>
      </controladapters>
   </browser>
</browsers>