在jsp中怎样调用javascript中的函数

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<title>My JSP 'checkBox.jsp' starting page</title>

function JoinDemo(){

alert("sss");

var aa = document.getElementsByName("checkname");

var bb = document.getElementById("bname");

if(bb.value=="全选"){

for( var i = 0;i<aa.length;i++){

aa[i].checked="true";

}

bb.value="取消"

}

else{

for(var i=0;i<aa.length;i++){

aa[i].checked = false;

};

value="全选"

}

</script>

</head>

<body>

<input type="checkbox" name="checkname" value="篮球">篮球

<input type="checkbox" name="checkname" value="足球">足球

<input type="checkbox" name="checkname" value="上网">上网

<input type="checkbox" name="checkname" value="看书">看书

</body>

</html>