JS 实现打印

<input id="btnPrint" type="button" value="打印预览" onclick=preview(1) />
<script>
function preview(oper)
{
if (oper < 10)
{
bdhtml=window.document.body.innerHTML;//获取当前页的html代码
sprnstr="<!--startprint"+oper+"-->";//设置打印开始区域
eprnstr="<!--endprint"+oper+"-->";//设置打印结束区域
prnhtml=bdhtml.substring(bdhtml.indexOf(sprnstr)+18); //从开始代码向后取html
prnhtmlprnhtml=prnhtml.substring(0,prnhtml.indexOf(eprnstr));//从结束代码向前取html
window.document.body.innerHTML=prnhtml;
window.print();
window.document.body.innerHTML=bdhtml;
} else {
window.print();
}
}
</script>

<!--startprint1-->要打印的内容<!--endprint1-->