<html>
<head>
<script type="text/javascript">
function myfunction(txt,a,b)
{
switch(txt)
{
case '+':
c = Number(a) + Number(b);
break;
case '-':
c = a - b;
break;
case '*':
c = a * b;
break;
case '/':
c = a / b;
break;
}
alert(c);
}
</script>
</head>
<body>
<form>
<p> Mini calculator! </p>
number 1: <input type="text" name="a" value="6"/><br />
number 2: <input type="text" name="b" value="2"/><br />
</p>
<input type="button" onclick="myfunction('+',a.value,b.value)" value="+">
<input type="button" onclick="myfunction('-',a.value,b.value)" value="-">
<input type="button" onclick="myfunction('*',a.value,b.value)" value="*">
<input type="button" onclick="myfunction('/',a.value,b.value)" value="/">
</form>
</body>
</html>