title: ASP.NET Page events calling twice
body: <p>I have code in one of my pages which is as given below:</p>
  
  <pre><code>&lt;asp:button id="btnTest" runat="server" onclick="btnTest_click" /&gt;
  &lt;div class="TomasForm"&gt;
          &lt;ul&gt;
              &lt;li&gt;
                  &lt;asp:Label ID="LineL" runat="server" AssociatedControlID="Lines" Text="&lt;%$ FieldLabelResources:Units, Line, false %&gt;" /&gt;
                  &lt;asp:DropDownList ID="Lines" runat="server" AutoPostBack="true" AppendDataBoundItems="true"
                      DataTextField="Name" DataValueField="Id" OnSelectedIndexChanged="Lines_SelectedIndexChanged"&gt;
                      &lt;asp:ListItem Text="&lt;%$ Resources:Common, SelectOne %&gt;" Value="-1" /&gt;
                  &lt;/asp:DropDownList &gt;
              &lt;/li&gt;
          &lt;/ul&gt;
      &lt;/div&gt;
  </code></pre>
  
  <p>My issue is when I change the Lines dropdownlist value, the page(page_load and Lines_SelectedIndexChanged events) is getting called twice.
  The page is behaving normal when I click btnTest button.</p>
  
  <p>Could anyone let me know why this is happening??</p>
  
  <p>Thanks,
  Mahesh</p>