Table enables double-clicking to edit, add, and delete rows

<table class="table table-bordered" id="para_table"> 
 <tr> 
  <th style="text-align:center" width="200">名称</th> 
  <th style="text-align:center" width="200">值</th> 
  <th style="text-align:center" width="100">操作</th> 
 </tr> 
 <tr> 
  <td style="text-align:center; " onclick="tdclick(this)"></td> 
  <td style="text-align:center; " onclick="tdclick(this)"></td> 
  <td style="text-align:center; " onclick="deletetr(this)"> 
  <button type="button" class="btn btn-xs btn-link">删除</button> 
  </td> 
 </tr> 
</table> 
 
<p id="addtrp" style="margin-top:-15px; width: 15%; float: right;"> 
 <button type="button" class="btn btn-xs btn-link" onclick="addtr()">添加</button> 
</p>

function save_para_table(){ 
 
 var tableinfo = gettableinfo(); 
 alert(tableinfo); 
 
 
} 
//get table infomation 
function gettableinfo(){ 
 var key = ""; 
 var value = ""; 
 var tabledata = ""; 
 var table = $("#para_table"); 
 var tbody = table.children(); 
 var trs = tbody.children(); 
 for(var i=1;i<trs.length;i++){ 
  var tds = trs.eq(i).children(); 
  for(var j=0;j<tds.length;j++){ 
   if(j==0){ 
    if(tds.eq(j).text()==null||tds.eq(j).text()==""){ 
     return null; 
    } 
    key = "key\":\""+tds.eq(j).text(); 
   } 
   if(j==1){ 
    if(tds.eq(j).text()==null||tds.eq(j).text()==""){ 
     return null; 
    } 
    value = "value\":\""+tds.eq(j).text(); 
   } 
  } 
  if(i==trs.length-1){ 
   tabledata += "{\""+key+"\",\""+value+"\"}"; 
  }else{ 
   tabledata += "{\""+key+"\",\""+value+"\"},"; 
  } 
 } 
 tabledata = "["+tabledata+"]"; 
 return tabledata; 
} 
 
function tdclick(tdobject){ 
 var td=$(tdobject); 
 td.attr("onclick", ""); 
 //1,取出当前td中的文本内容保存起来 
 var text=td.text(); 
 //2,清空td里面的内容 
 td.html(""); //也可以用td.empty(); 
 //3，建立一个文本框，也就是input的元素节点 
 var input=$("<input>"); 
 //4，设置文本框的值是保存起来的文本内容 
 input.attr("value",text); 
 input.bind("blur",function(){ 
  var inputnode=$(this); 
  var inputtext=inputnode.val(); 
  var tdNode=inputnode.parent(); 
  tdNode.html(inputtext); 
  tdNode.click(tdclick); 
  td.attr("onclick", "tdclick(this)"); 
 }); 
 input.keyup(function(event){ 
  var myEvent =event||window.event; 
  var kcode=myEvent.keyCode; 
  if(kcode==13){ 
   var inputnode=$(this); 
   var inputtext=inputnode.val(); 
   var tdNode=inputnode.parent(); 
   tdNode.html(inputtext); 
   tdNode.click(tdclick); 
  } 
 }); 
 
 //5，将文本框加入到td中 
 td.append(input); 
 var t =input.val(); 
 input.val("").focus().val(t); 
//    input.focus(); 
 
 //6,清除点击事件 
 td.unbind("click"); 
} 
function addtr(){ 
 var table = $("#para_table"); 
 var tr= $("<tr>" + 
  "<td onclick=&#39;tdclick(this)&#39;>"+"</td>" + 
  "<td onclick=&#39;tdclick(this)&#39;>"+"</td>" + 
  "<td align=&#39;center&#39; onclick=&#39;deletetr(this)&#39;><button type=&#39;button&#39; class=&#39;btn btn-xs btn-link&#39; >"+"删除"+"</button></td></tr>"); 
 table.append(tr); 
} 
function deletetr(tdobject){ 
 var td=$(tdobject); 
 td.parents("tr").remove(); 
}