asp.net setting validationexpression dynamically
<p>I have several pages in my form where I need to validate Email address. Rather than set validationexpression in each page , I want to store the Regex string in a Constants class as a string constant and do some thing like</p>

<pre><code>  ValidationExpression="&lt;%=Tickets.App_Code.Constants.EmailRegex%&gt;"
</code></pre>

<p>I know I can do this in Code Behind but I want to do it declaratively in Aspx page. However the above does not work as the text is not replaced by the contents of the constant. In asp.net we have syntax like <code>&lt;%# %&gt;(Binding) , &lt;%= %&gt; (Invoke code)</code>.</p>

<p>I searched the web but I cannot find much documentation on this area. Can somebody help ?</p>
