aspx submit form error
<p>Im working with asp.net  framework 4.0 and I have this code:</p>

<p>form id="form1" runat="server" method="get" action="Profile.aspx"</p>

<pre><code> // some code
</code></pre>

<p>asp:Button runat="server" ID="SubmitButton" Text="Submit"</p>

<p>Each time i click the submit button i get this error:</p>

<p><strong>Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that  configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.</strong> </p>

<p>any idea how to fix it ???</p>
