点击按钮，没有输出什么原因？
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>函数传参</title>
<script type="text/JavaScript">
function add3(x,y,z)
{
var x=5;
var y=8;
var z=3;
sum = x + y +z;
document.write(x+"、"+y+"、"+z+"和:"+sum+"<br/>");
}
</script>
</head>
<body>
<input type="button" value="点击" oncilik=" add3()">
</body>
</html>
