Submit to new view in CodeIgniter

I have one controller with an index() and a newFun开发者_JAVA百科ction(). When my index function loads, it loads the first view that I need. I have a submit button on that view:

<div class="btn"><input type="submit" name="submit" id="submit_button" value="Pay"></input></div>

I want that submit button to load the newFunction(), as the new page, right now it is loading the newFunction()/view under the index view.

This is what I call in my index function to try and get the new view to load as a new page. Except it loads it right under it.

$submit = $this->input->post("submit");
if($submit == "Pay") {
    $this->pay($postData);//pay is the name of newFunction();
}

public function index()
{
    if($this->input->post("submit") == "Pay")
    {
        $this->pay($postData);//pay is the name of newFunction();
        return; // With this, rest of the code wont execute.
    }
}