title: Setting form validation rules in CodeIgniter
body: <p>I have these issue where I want to set a rules on three input forms of type "text", my rule is that <strong>at least</strong> one of these three has values (<strong>either of the three</strong>), I have no idea how to set them in CI, because they are altogether executed when run() is triggered, any on of you guys knows how to set these kind of rules to form validation in CI please do share your knowledge.</p>