How to add javascript to nop commerce.

I am trying to add a reversble counter to nop commerce. Im using v2.8 no source, im using jquery countdown keith wood, and to load the javascript im adding @Html.AddScriptParts("~/Scripts/jquery.countdown.js");   to the header.cshtml.

When i try to display the page i get redirected to the error.page.

Can it be the script that is breaking up the site, or is it my fault, not loading the file correctly?

Try this:
Html.AppendScriptParts ("...");

Also not working.