There is the following code:
    <div id="main">
        <div id="first">
            First item
        </div>
        <div id="second">
            Second item
        </div>
        <div id="third">
            Third item
        </div>
    </div>
CSS styles:
    #first {
        background-color: yellow;
    }
    #second {
        background-color: blue;
    }
    #third {
        background-color: green;
    }
    html, body, #main, #first, #second, #third {
        height: 100%;
    }
There are 3 div in main div and user scrolls in order to go to the bottom of the screen. I want to do the following thing: when user scrolls with mousewheel the first time he goes to "second" div, the second time - "third" div. This feature has been realized on the following site: some site. Please, tell me some advice. Thanks.
 
     
    