<html> <body> <img src="/static/demo/images/eg_planets.jpg" usemap="#planetmap" /> <map name="planetmap"> <area id="venus" shape="circle" coords="180,139,14" alt="The planet Venus" href="/static/demo/html/venus.html" /> </map> <p>"Venus" 的替代文本是: <script type="text/javascript"> x=document.getElementById('venus'); document.write(x.alt); </script> </p> </body> </html>