title: Required field validator not working when OnClientClick is added in the button
body: <p>hi i have a RequiredFieldValidator Like this</p>
  
  <pre><code>&lt;asp:TextBox ID="txtEmployeeID" runat="server" MaxLength="255" CssClass="txt" 
      OnTextChanged="txtEmployeeID_TextChanged" AutoPostBack="True" 
      ValidationGroup="Save" &gt;&lt;/asp:TextBox&gt;     
  &lt;asp:RequiredFieldValidator ID="rfvEmployeeID" runat="server" 
      ErrorMessage="Employee ID is required information."
      ControlToValidate="txtEmployeeID" Display="None" ValidationGroup="Save"
      SetFocusOnError="True"&gt;&lt;/asp:RequiredFieldValidator&gt;
  </code></pre>
  
  <p>and a button like this</p>
  
  <pre><code> &lt;asp:Button ID="btnBlockUser" runat="server" Text="Block User" 
      CssClass="submitBtn " OnClick="btnBlockUser_Click" 
      OnClientClick="javascript:return confirm('Are you sure want to Block this user ?')"
      ValidationGroup="Save" /&gt;
  </code></pre>
  
  <p>Now the problem is that if i remove the OnClientClick in the button  the RequriedFieldValidator works fine if i put it back there page posts back without showing any error message can some one explain why this is happenening??</p>