DENERIK,
<!DOCTYPE HTML>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
a {
display: none;
}
.a120 {
width: 230px;
position: relative;
top: 70px;
left: 13px;
display: inline-table;
background: rgba(255, 255, 255, 0.3);
text-align: center;
font-size: 110%;
color: rgba(0,0,0,1);
text-shadow: 0px 0px 14px rgba(255, 255, 255, 1);
}
</style>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script>
$(function() {
var a = $('[name^="a"]'),
b = $("a");
a.click(function() {
var c = 0;
a.each(function(a, b) {
this.checked && (c += a + 1)
});
b.hide().eq(c).show()
});
b.eq(0).show()
});
</script>
</head>
<body>
<input type="checkbox" name="a1"><span title="...">Графа 1</span>
<input type="checkbox" name="a2"><span title="...">Графа 2</span>
<a href="ССЫЛКА 1" download="download"><div class="a120">СКАЧАТЬ1</div></a>
<a href="ССЫЛКА 2" download="download"><div class="a120">СКАЧАТЬ2</div></a>
<a href="ССЫЛКА 3" download="download"><div class="a120">СКАЧАТЬ3</div></a>
<a href="ССЫЛКА 4" download="download"><div class="a120">СКАЧАТЬ4</div></a>
</body>
</html>