title: Querystring - Add values to querystring in c#
body: <p>How can I add values to querystring?</p>
  
  <p>I'm trying to do this:</p>
  
  <pre><code>String currurl = HttpContext.Current.Request.RawUrl;
  var querystring = HttpContext.Current.Request.QueryString.ToString();
  
  var PrintURL = currurl + (String.IsNullOrEmpty(querystring)) ?
      HttpContext.Current.Request.QueryString.Add("print", "y") : string.Empty;
  </code></pre>
  
  <p>But I keep getting this error:</p>
  
  <blockquote>
    <p>Cannot implicitly convert type 'string' to 'bool'</p>
  </blockquote>
  
  <p>all i'm trying to do is get current url and add ?pring=y to querystring</p>