给span赋值失效

不能正常运行,
示例代码:

代码


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script language="javascript" type="text/javascript">
    function test()
    {
        document.getElementById("span1").innerText="abcd";
        alert(document.getElementById("span1").innerText);
    }
</script>
</head>

<body >
<span id="span1">0000000</span>
<br>
<input type="button" onclick="test()" value="测试" />
</body>
</html>

分析:由于页面代码加载顺序问题,把js代码放在span后面,就OK了!
示例代码:

代码


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>

</head>

<body >
<span id="span1">0000000</span>
<br>
<input type="button" onclick="test()" value="测试" />
</body>
</html>
<script language="javascript" type="text/javascript">
    function test()
    {
        document.getElementById("span1").innerText="abcd";
        alert(document.getElementById("span1").innerText);
    }
</script>