<html>
<head>
<meta charset="utf-8">
<title>Başlıksız Belge</title>
</head>
<body>
<input type="button" id="t1" value="1" >
<input type="button" id="t10" value="10">
<input type="button" id="t50" value="50"><br/>
<div><a>Sonuç:</a><a id="sonuc">0</a> </div>
<script type="text/javascript">
var t1 =document.getElementById("t1");
var t10 =document.getElementById("t10");
var t50 =document.getElementById("t50");
var sonuc =document.getElementById("sonuc");
t1.onclick=topla;
t10.onclick=topla;
t50.onclick=topla;
function topla()
{ sonuc.innerHTML= Number(sonuc.innerHTML)+Number(this.value); }
</script>
</body>
</html>