https://sky7ventures.com/js/fadeInText.js

1var faderIndex = 0,
2        faders = $('.fadey');
3    
4    function nextFade() {
5        $(faders[faderIndex]).fadeOut(1000, function() {
6            faderIndex++;
7            if (faderIndex >= faders.length)
8                faderIndex = 0;
9            $(faders[faderIndex]).fadeIn(1000, nextFade);
10        });
11    }
12    nextFade();
13
14
15
16    // checkbox enable and disable
17
18    // var checker = document.getElementById('checkme');
19    var sendbtn = document.getElementById('sendNewSms').disabled = true;
20    // checker.onchange = function() {
21    //   sendbtn.disabled = !!this.checked;
22    // };
23
24    var checker = $("#checkme");
25    var sendbtn = $("#sendNewSms");
26
27checker.click(function() {
28    sendbtn.attr("disabled", !checker.is(":checked"));
29});