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<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>输出Hello World</title>
<script  type="text/javascript">  

if( confirm("是否开始运行程序?") ){ 
    var j=prompt("请输入连续输出'hello world!'的次数:",1); 

    if( j < 0 )alert("请输入大于0的整数");  
    for(var i=0;i<j;i++){
        if( i==0 )document.write("<h3>开始输出</h3>");
        document.write("<h3>Hello World</h3>");
        if( i==j-1 )document.write("<h3>结束输出,共输出了"+j+"次.</h3>");
    } 

}else{
    alert("你已经放弃了执行程序"); 
}


</script>
</head>

<body>

</body>
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