<html><body><iframe src="/example/hdom/frame_a.html" id="frame1"></iframe><br /><br /><script type="text/javascript">document.write("The iframe's id: ");document.write(document.getElementsByTagName("iframe")[0].id);document.write("<br /><br />");document.write("An alternate way: ");document.write("<br />");document.write("The iframe's id: ");document.write(document.getElementById("frame1").id);</script></body></html>