Simple example: Show or hide secondary paragraph by clicking a link (requires jQuery).

sample.html

<p>
    Your visible text.
</p>

<a id="toggle_text" href="#!">More...</a>

<p id="hidden_text" style="display: none;">
    Your hidden text.
</p>

<script>
    // wait for document to be fully rendered
    $('document').ready(function() {

        // capture click event
        $('body').on('click','#toggle_text',function(e) {

            console.log('ok');

            // prevent default link clicking action
            e.preventDefault();

            // define the target object you want to control
            var target = $('#hidden_text');
            var link = $('#toggle_text');

            // toggle the visibility and link text
            if (target.is(":visible")) {

                // hides target and sets link text to "More..."
                target.hide();
                link.html('More...');
            } else {

                // shows target and sets link text to "Hide..."
                target.show();
                link.html('Hide...');
            }
        });
    });
</script>