js的prototype的例子三

<script>
function TestObjectA()
{
this.MethodA = function()
{
alert('TestObjectA.MethodA()');
}
}

function TestObjectB()
{
this.MethodB = function()
{
alert('TestObjectB.MethodB()');
}
}

TestObjectB.prototype = new TestObjectA();
var dd = new TestObjectB();
dd.MethodB();
dd.MethodA();

</script>