Dynamically change value of hidden field
<p>For an existing site, I have to pass values in hidden fields from a form that's loaded by different pages (eg. City1.aspx, City2.aspx, City3.aspx, etc.), but they are loaded inside an iframe. I also have to dynamically change the value of at least one of those hidden field (let's call it "source") based on the city page loading it. I am familiar with PHP and JavaScript/JQuery, but I have no idea how to do this in C#.</p>

<p>I've found tutorials on retrieving the file name (sans extension) via JavaScript. I think I can still get the city even if the form is in an iframe, but I'd like to keep to the site's conventions and use C# if possible.</p>

<p>Code snippets or links to possible solutions would be much appreciated.</p>
