title: Merge 2 columns from datatable in datatextfield from dropdownlist
body: <pre><code>var id = Session["staff_id"].ToString()
  
  //I have datatable with 5 columns
  
  DataTable dt = function_return_Datatable(id);
  
  dropdownlist1.DataSource = dt;
  
  /*in DataTextField I want to merge two columns of DataTable, dt.columns [1] is First Name and dt.columns [2] is LastName*/
  
  //I tried this way to merge them, but no results
  dropdownlist1.DataTextField = dt.Columns[1].ToString()+" "+dt.Columns[2].ToString();
  
  dropdownlist1.DataValueField = dt.Columns[0].ToString();
  dropdownlist1.DataBind();
  </code></pre>
  
  <p>Any ideas for how to merge these two columns?</p>