SO fiddle

Test Fiddle mainly for SO Questions

by bluey

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/overcast/jquery-ui.css">
<div class="thumb">Click me</div>
<div class="thumb">Click me</div>
<div class="thumb">Click me</div>
<div class="thumb">Click me</div>
<div class="thumb">Click me</div>

JavaScript

$('.thumb').each(function (i) {
    $(this).click(function () {
        alert (i+1); //index starts with 0, so add 1 if you want 1 first
    });
});