title: Drop Down Control Selected Index change event
body: <p>In my webfrom in asp.net I have a grid view a button, a text box and a Dropdownlist.
  I have a method like this to call and select the data in to my grid view.</p>
  
  <pre><code>public void fillGridByAuthor(string searchKey)
  {
      GVDetails.DataSource = new ViewAllBKByAuthorOP().searchAuthorByAUNM(searchKey);
      GVDetails.DataBind();
  }
  </code></pre>
  
  <p>This is my business layer method. </p>
  
  <pre><code> public DataTable searchAuthorByAUNM(string searchKey)
  {
      string query2 = "EXEC SelectBooksDTByAuthor'" + searchKey + "'";
      return new DataAccessLayer().executeTable(query2);
  }
  </code></pre>
  
  <p>I'm calling fillGridByAuthor method in form in the drop downlist selected index change event like this. </p>
  
  <pre><code> protected void DDAuthor_SelectedIndexChanged(object sender, EventArgs e)
   {
      fillGridByAuthor(DDAuthor.Text);
  
   }
  </code></pre>
  
  <p>and in the button click event like this</p>
  
  <pre><code> protected void btnSearch_Click(object sender, EventArgs e)
   {
       fillGridByAuthor(txtAuName.Text);
  
   }
  </code></pre>
  
  <p>It is working fine when the button is clicked. Though I select the same Item in the drop down list, it doesn't give me the same output.
  What's incorrect here?  </p>