function GetXmlHttp() // 获得xmlHttp的方法
		{
			var xmlHttp = null;
			try {
				// Firefox, Opera 8.0+, Safari
				xmlHttp = new XMLHttpRequest();
			} catch (e) {
				// Internet Explorer
				try {
					xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
				} catch (e) {
					xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
				}
			}
			return xmlHttp;
		}

		function fachange(id,said){ 
			xmlHttp = GetXmlHttp()// 获得xmlHttp
			if (xmlHttp == null) {
				alert("浏览器不支持xmlHttpRequest请求")
				return;
			}
			var actionurl=document.getElementById("actionurl").value; 
			var url = actionurl+"/include/ajax.check.php?action=fa&pid="+id;
			xmlHttp.onreadystatechange = function(){
				if (xmlHttp.readyState == 4 || xmlHttp.readyState == "complete") {
					respValue = xmlHttp.responseText;
					//alert(respValue); 
					document.getElementById(said).options.length=1;
					var salist=respValue.split("csplit");
					//alert(salist);
					if (salist[0].split("clinks").length > 1) {
						for ( var i = 0; i < salist.length; i++) { 
							var cacategory=salist[i].split("clinks");
							document.getElementById(said).options.add(new Option(cacategory[2], cacategory[1]));
						}
					}
				} 
			};
			xmlHttp.open("get", url, true);
			xmlHttp.send(null);
		}
		
		function checkusers(username){
			
			xmlHttp = GetXmlHttp()// 获得xmlHttp
			if (xmlHttp == null) {
				alert("浏览器不支持xmlHttpRequest请求")
				return false;
			}
			var actionurl=document.getElementById("actionurl").value; 
			var url = actionurl+"/include/ajax.check.php?action=checkuser&username="+username;
			xmlHttp.onreadystatechange = function(){
				if (xmlHttp.readyState == 4 || xmlHttp.readyState == "complete") {
					respValue = xmlHttp.responseText; 
					//alert(respValue);
					if(respValue!="false"){
						document.getElementById("registername").style.display="block";
						document.getElementById("registername").innerHTML="<font color=red>*用户名已存在</font>";
					}else{
						document.getElementById("registername").style.display="none";
						document.getElementById("registername").innerHTML="";
					}
				} 
			};
			xmlHttp.open("get", url, true);
			xmlHttp.send(null);
		}