只有最后20分了,求一具体表格删减js代码

Question

www.bjcan.com/hengxing/more.asp自己搜索

Answer 1

默认为3行，不能再少了，只能增加
<form name="form1" method="post" action="">
  <input type="button" name="Submit" value="-"  onclick="deleteRow()">
  <input name="num" type="text" value="3" size="4" maxlength="4">
  <input type="button" name="Submit2" value="+" onclick="insertRow()">
  <br>
  <table id="table1" width="500" border="0" cellspacing="0" cellpadding="0">
    <tr>
      <td width="87"><select name="select"></select></td>
      <td width="277"><input type="text" name="textfield1"></td>
      <td width="136"><input type="button" name="1" value="1"></td>
    </tr>
    <tr>
      <td><select name="select2"></select></td>
      <td><input type="text" name="textfield2"></td>
      <td><input type="button" name="2" value="2"></td>
    </tr>
    <tr>
      <td><select name="select3"></select></td>
      <td><input type="text" name="textfield3"></td>
      <td><input type="button" name="3" value="3"></td>
    </tr>
  </table>
</form>
<script language=javascript>
function deleteRow()
{
var obj=document.getElementById("table1")
var rowIndex=obj.childNodes[0].childNodes.length;
if(rowIndex>3)
{
document.getElementById("num").value=document.getElementById("num").value-parseInt(1)
obj.deleteRow(rowIndex-parseInt(1));
}
}
function insertRow()
{
var obj=document.getElementById("table1")
var rowIndex=obj.childNodes[0].childNodes.length;
var objTR=obj.insertRow(rowIndex);
var objTD1=objTR.insertCell();
var objTD2=objTR.insertCell();
var objTD3=objTR.insertCell();
rowIndex2=parseInt(rowIndex)+parseInt(1)
objTD1.innerHTML=obj.childNodes[0].childNodes[rowIndex-1].childNodes[0].innerHTML.replace(/(name=)(\")*(select)(\d)(\2)/gi,"$1$2$3"+rowIndex2+"$5")
objTD2.innerHTML=obj.childNodes[0].childNodes[rowIndex-1].childNodes[1].innerHTML.replace(/(name=)(\")*(textfield)(\d)(\2)/gi,"$1$2$3"+rowIndex2+"$5")
objTD3.innerHTML=obj.childNodes[0].childNodes[rowIndex-1].childNodes[2].innerHTML.replace(/(=)(\")*(\d)(\2)/gi,"$1$2"+rowIndex2+"$4")
document.getElementById("num").value=parseInt(document.getElementById("num").value)+parseInt(1)
}
</script>