在使用DHTML進行編程時比較有用，防止瀏覽器在請求中，死掉

var ?xml? = ?GenXMLData(tableName,?fieldID,? "" ,? "" );
???? var ?content? = ? " < table?height=100%?width=100%><tr><td><div?id='divDoing'?style ='position:absolute;?left:500px;?top:136px;?width:196px;?height:105px;?z- index:1;'><div?align='center'><p><img?src='../Images/doing.gif'?width ='32'?height='32'/></p><p><br/>正在查詢、請稍候……</p> </div></div></td></tr></table> " ;
????contentTD.innerHTML? = ?content;
???????? var ?XmlHttp = new ?ActiveXObject( " Microsoft.XMLHTTP " );
????XmlHttp.onreadystatechange = function () {
??????? if (XmlHttp.readyState == 4 ) {
???????????? if (XmlHttp.status == 200 )
???????????? {
??????????????contentTD.innerHTML? = ?XmlHttp.responseText;
??????????????firstPost? = ? true ;
????????????}
???????????? else
????????????contentTD.innerHTML? = ?content?;
????????}
????}
????XmlHttp.open( " post " ,webFile, true );
????XmlHttp.send(xml);