原生态Ajax无刷新评论和顶踩代码（记事本打造，无验证）

<script type="text/javascript">
	var xhr=false;
	var actionType;
	//todo:
	var sId=1;
　　function createXmlHttp() {//创建xhr对象
            var xhobj = false;
            try {
                xhobj = new ActiveXObject("Msxml2.XMLHTTP"); // ie msxml3.0+
            } catch (e) {
                try {
                    xhobj = new ActiveXObject("Microsoft.XMLHTTP"); //ie msxml2.6
                } catch (e2) {
                    xhobj = false;
                }
            }
            if (!xhobj && typeof XMLHttpRequest != 'undefined') {// Firefox, Opera 8.0+, Safari
                xhobj = new XMLHttpRequest();
            }
            return xhobj;
        }
	window.onload=function(){
		xhr=new createXmlHttp();
	}
	function doSupport(isSupport){
		xhr.open("POST","DoSupport.ashx",true);
		xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
		xhr.onreadystatechange=watching;
		if(isSupport){
			actionType=1;
			xhr.send("sId="+sId+"&isSup="+actionType);
		}
		else{
			actionType=0;
			xhr.send("sId="+sId+"&isSup="+actionType);
		}	
	}
	function watching(){
		if（xhr.readyState>=4）{
			if(xhr.status==200){
				var resText=xhr.responseText;
				var resArr=resText.split(",");
				if(resArr[0]=="ok"){
					if(actionType==1){
						document.getElementById("spanSup").innerHtml=resArr[1];
					}
					else{
						document.getElementById("spanDisSup").innerHtml=resArr[1];
					}
				}
				else{
					//todo:
				}	
			}	
		}
	}
	function AddComment(){
		xhr.open("POST","DoAddComments.ashx",true);
		xhr.setreadystatechange=watchingComments;
		xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
		var urlData="sId"+sId+"&txtContents="+document.getElementByIdea("txtComments").value;
		xhr.send(urlData);
	}
	function watchingComments(){
		if(xhr.readyStates>=4){
			if(xhr.status==200){
				var resText=xhr.responseText;
				if(resText=="ok"){
					var commentsTable=document.getElementById("txtComments");//获取评论的表格对象
					var newRow=commentsTable.insertRow(commentsTable.row.length);
					var nTd1=newRow.insertCell();
					var nTd2=newRow.insertCell();
					nTd1.innerHtml=nowLoginUser;
					nTd2.innerHtml=document.getElementById("txtComments").value;
				}
				else{
					//todo:
				}
			}
			else{
				alert(xhr.status);
			}
		}
		
	}



<script>

 1 <br><script type="text/javascript">
 2 ?
 3     var xhr=false;
 4     var actionType;
 5     //todo:
 6     var sId=1;
 7 　　function createXmlHttp() {//创建xhr对象
 8             var xhobj = false;
 9             try {
10                 xhobj = new ActiveXObject("Msxml2.XMLHTTP"); // ie msxml3.0+
11             } catch (e) {
12                 try {
13                     xhobj = new ActiveXObject("Microsoft.XMLHTTP"); //ie msxml2.6
14                 } catch (e2) {
15                     xhobj = false;
16                 }
17             }
18             if (!xhobj && typeof XMLHttpRequest != 'undefined') {// Firefox, Opera 8.0+, Safari
19                 xhobj = new XMLHttpRequest();
20             }
21             return xhobj;
22         }
23     window.onload=function(){
24         xhr=new createXmlHttp();
25     }
26     function doSupport(isSupport){
27         xhr.open("POST","DoSupport.ashx",true);
28         xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
29         xhr.onreadystatechange=watching;
30         if(isSupport){
31             actionType=1;
32             xhr.send("sId="+sId+"&isSup="+actionType);
33         }
34         else{
35             actionType=0;
36             xhr.send("sId="+sId+"&isSup="+actionType);
37         }   
38     }
39     function watching(){
40         if（xhr.readyState>=4）{
41             if(xhr.status==200){
42                 var resText=xhr.responseText;
43                 var resArr=resText.split(",");
44                 if(resArr[0]=="ok"){
45                     if(actionType==1){
46                         document.getElementById("spanSup").innerHtml=resArr[1];
47                     }
48                     else{
49                         document.getElementById("spanDisSup").innerHtml=resArr[1];
50                     }
51                 }
52                 else{
53                     //todo:
54                 }   
55             }   
56         }
57     }
58     function AddComment(){
59         xhr.open("POST","DoAddComments.ashx",true);
60         xhr.setreadystatechange=watchingComments;
61         xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
62         var urlData="sId"+sId+"&txtContents="+document.getElementByIdea("txtComments").value;
63         xhr.send(urlData);
64     }
65     function watchingComments(){
66         if(xhr.readyStates>=4){
67             if(xhr.status==200){
68                 var resText=xhr.responseText;
69                 if(resText=="ok"){
70                     var commentsTable=document.getElementById("txtComments");//获取评论的表格对象
71                     var newRow=commentsTable.insertRow(commentsTable.row.length);
72                     var nTd1=newRow.insertCell();
73                     var nTd2=newRow.insertCell();
74                     nTd1.innerHtml=nowLoginUser;
75                     nTd2.innerHtml=document.getElementById("txtComments").value;
76                 }
77                 else{
78                     //todo:
79                 }
80             }
81             else{
82                 alert(xhr.status);
83             }
84         }
85          
86     }
87  
88  
89  
90 <script>