vasyakrn,
на всякий случай у вас ошибка в 4 строке
<!DOCTYPE HTML>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
.info {
display: none;
}
</style>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script>
$(function(){
var but = $('[type="submit"]'), sel = $('.info-ruler'), info = $('.info');
but.click(function() {
info.hide();
$('#' + sel[0].value + '-' + sel[1].value).show();
});
});
</script>
</head>
<body>
<select class="info-ruler">
<option value="a">Info 1</option>
<option value="b">Info 2</option>
<option value="c">Info 3</option>
</select>
<select class="info-ruler">
<option value="1">Info 1</option>
<option value="2">Info 2</option>
</select>
<div class="info" id="a-1">Information block 1</div>
<div class="info" id="a-2">Information block 2</div>
<div class="info" id="b-1">Information block 4</div>
<div class="info" id="b-2">Information block 5</div>
<div class="info" id="c-1">Information block 6</div>
<div class="info" id="c-2">Information block 7</div>
<input type="submit" value="Генерирувать">
</body>
</html>