/// <summary>
/// Returns the value of a mandatory item in the FormCollection
/// </summary>
/// <param name="items"></param>
/// <param name="key"></param>
/// <returns></returns>
public static string GetRequiredString(this FormDataCollection items, string key)
{
if (items.HasKey(key) == false)
{
throw new ArgumentNullException("The " + key + " query string parameter was not found but is required");
}
return(items.Single(x => x.Key.InvariantEquals(key)).Value);
}
