概述
向文档中写入一串文本，并紧跟着一个换行符。
语法
document.writeln(line);
参数
line为包含文本的字符串
示例
document.writeln("<p>enter password:</p>");
备注
document.writeln 和 document.write 一样，但是会添加一个换行符。
Note: document.writeln (like document.write) does not work in XHTML documents (you'll get a "Operation is not supported" (
NS_ERROR_DOM_NOT_SUPPORTED_ERR) error on the error console). This is the case if opening a local file with a .xhtml file extension or for any document served with an application/xhtml+xml MIME type. More information is available in the W3C XHTML FAQ.