js创建元素笔记

function showAreaData(weekId){
			
				var currTR = event.srcElement.parentNode;
				
				if(hasData==true && lastCell == weekId){
					
					for(var s = 1 ; s <= n ; s ++){
						currTR.parentNode.removeChild(currTR.nextSibling);
					}
					hasData = false;
					
				}else{
					if(hasData == true && lastCell != weekId){
						for(var s = 1 ; s <= n ; s ++){
							lastTR.parentNode.removeChild(lastTR.nextSibling);
						}
						hasData = false;
					}
					var productType = form.productType.value;
					var businessType = form.businessType.value;
					var serviceLevel = form.serviceLevel.value;
					var customGroup = form.customGroup.value;
					var areaId = form.areaNo.value;
					
					//alert(areaId+" "+weekId+" "+productType+" "+businessType+" "+serviceLevel+" "+customGroup);
					
					var xmlhttp = createXHR();
				  	xmlhttp.onreadystatechange = function(){
				  		if(xmlhttp.readyState == 4){
					        if(xmlhttp.status == 200){
					        	var responseText = xmlhttp.responseText;
					        	
					        	var trs = responseText.split("<tr>");
					        	
					        	for(var i = 1 ; i < trs.length; i ++ ){
					        		n = i;
					        		var tr = trs[i].split("</tr>")[0];
					        		//alert(tr);
					        		var tds = tr.split('<td>');
					        		//创建tr
					        		var trNode = document.createElement("<tr id='TR_"+weekId+""+i+"' style='display:block;'></tr>");
					        		
					        		for(var j = 1 ; j < tds.length; j ++){
					        			var td = tds[j].split("</td>")[0];
					        			//alert(td);
					        			//创建td并添加到tr
					        			var tdNode = document.createElement("<td align='right'></td>");
					        			tdNode.innerHTML = td;
					        			trNode.appendChild(tdNode);
					        		}
					        		//追加tr
					        		currTR.parentNode.insertBefore(trNode,currTR.nextSibling);
					        	}
					        }
			    		}
				  	}
				  	
				    var URL = "TotalAnalysisWeek.action?flag=getAreaData&weekId="+weekId+"&productType="+productType
				    	+"&businessType="+businessType+"&serviceLevel="+serviceLevel+"&customGroup="+customGroup
				    	+"&areaId="+areaId;
				    
				    xmlhttp.open("post",URL,false);
				    
				    xmlhttp.send(null);
				    
					hasData = true;
					lastCell = weekId;
				}
				lastTR = currTR;
			}