function addRow(){
//其中mainTb时table的Id
//mainBody时表格主体的Id
//表格结构：<table id="mainTb"><tbody id="mainBody"><tr><td>。。。。。。</td></tr></tbody></table>
var tableObj = document.getElementById("mainTb");
var tableBodyObj = document.getElementById("mainBody");
var newRowObj = document.createElement("<tr name='trN' onMouseOver='tOn(this);' onMouseOut='tOn2(this);' onclick='aler
();'>");
var newtext1 = document.createElement("<td class='listdata'>");
var newtext2 = document.createElement("<td class='listdata'>");
var newtext3 = document.createElement("<td class='listdata'>");
var newtext4 = document.createElement("<td class='listdata'>");
var newtext5 = document.createElement("<td class='listdata'>");
var newtext6 = document.createElement("<td class='listdata'>");
var newtext7 = document.createElement("<td class='listdata'>");
var num=eval(document.getElementById("flag").value)+1;
document.getElementById("flag").value=num;
newtext1.innerHTML=num;
newtext2.innerHTML=document.getElementById("flight").value;
newtext3.innerHTML=document.getElementById("lk_strt").value;
newtext4.innerHTML=document.getElementById("lk_seat").value;
newtext5.innerHTML=document.getElementById("lk_bdno").value;
newtext6.innerHTML=document.getElementById("lkdate").value;
newtext7.innerHTML="否";
newRowObj.appendChild(newtext1);
newRowObj.appendChild(newtext2);
newRowObj.appendChild(newtext3);
newRowObj.appendChild(newtext4);
newRowObj.appendChild(newtext5);
newRowObj.appendChild(newtext6);
newRowObj.appendChild(newtext7);
tableBodyObj.appendChild(newRowObj);
}