title: How to pass null value in the parameter
body: <p>I have a page that loads some request history based on the parameter selected by the user. But for the first time it will load all the request history. So I wrote the procedure that takes current user and if user puts any parameter it takes it as well, else all the parameters except the current user will be null. Now int the code behind page, I am calling the method from the business logic but having some problem with the parameter as this time it will show everything according to the current user id, and other parameter will null. Here is part of the code I am getting error.</p>
  
  <pre><code>var candidateRequestHistory = CandidateRequestManager.GetCandidateRequestHistory(((int)Session[CommonHelper.Constants.(CURRENT_CANDIDATE)),'','',0,'','')]);
                  grdCandidateRequestHistory.DataSource = candidateRequestHistory;
                  grdCandidateRequestHistory.DataBind();
  </code></pre>
  
  <p>want to pass all the parameters null except the HumanResourceID.
      (int HumanresourceID,String framework,String SkillName,int SkillLevel,DateTime fromDate,DateTime toDate) </p>