innerHtml小例子
<html><head><script type="text/javascript">function getInnerHTML() { //alert(document.getElementById("id1").innerHTML); if(document.getElementById("id1").innerHTML != ""){alert("true") }else{alert("false"); } }</script></head><body><table border="1"><tr id="tr1"><th>Firstname</th><th>Lastname</th></tr><tr id="tr2"><td id="id1">Peter</td><td>Griffin</td></tr></table><br /><input type="button" onclick="getInnerHTML()" value="Alert innerHTML of table row" /></body></html>