keystation,
<!DOCTYPE html>
<html lang="en">
<head>
<script src="http://code.jquery.com/jquery-1.11.1.js"></script>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<div>
<a id="div1">Текст 1</a>
</div>
<button id="button1" onclick="Text1()">Текст 1</button>
<button id="button2" onclick="Text2()">Текст 2</button>
</body>
</html>
<script>
function Text1(){
$('#div1').html("Текст 1");
}
function Text2(){
$('#div1').html("А это Текст 2");
}
</script>