我是 Javascript 的新手，正在通过一本教科书学习基础知识，该教科书侧重于 IE 7+ 和 Firefox 2+ 中的应用程序。但是，我正在使用 Chrome 并在运行书中给出的程序时遇到以下错误：“阻止了一个原始框架 'null' 访问跨源框架。” 谁能告诉我是什么导致了错误以及如何修复它？这两个程序如下。
//This is the program being loaded into the browser
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Example</title>
<script type="text/javascript">
function calcFactorial(factorialNumber){
var factorialResult = 1;
for(;factorialNumber>0;factorialNumber--) factorialResult *= factorialNumber;
return factorialResult;
}
</script>
</head>
<frameset cols="100%,*">
<frame name="fraCalcFactorial" src="calcfactorial.htm"/>
</frameset>
</html>
下面是src文件
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Example</title>
<script type="text/javascript">
function butCalculate_onclick(){
try{
if (window.top.calcFactorial == null)
throw "This page is not loaded within the correct frameset";
if (document.form1.txtNum1.value == "")
throw "!Please enter a value before you calculate its factorial";
if (isNaN(document.form1.txtNum1.value))
throw "!Please enter a valid number";
if (document.form1.txtNum1.value < 0)
throw "!Please enter a positive number";
}
catch(exception){
if (typeof(exception) == "string"){
if (exception.charAt(0) == "!"){
alert(exception.substr(1));
document.form1.txtNum1.focus();
document.form1.txtNum1.select();
}
else alert(exception);
}
else alert("The following error occurred: " + exception.message);
}
}
</script>
</head>
<body>
<form action="" name="form1">
<input type="text" name="txtNum1" size="3" /> factorial is
<input type="text" name="txtResult" size="25" /><br/>
<input type="button" value="Calculate Factorial"
name="butCalculate" onclick="butCalculate_onclick()" />
</form>
</body>
</html>