/*
以下代码是尝试进行AJAX用户注册练习

参考资料：http://www.alixixi.com/Dev/Web/ajax/ajax2/2007/2007032530345.html

修改人：蔡刚

时间：2008-5-31

*/

// 直接先创建 XMLHttpRequest 对象，
var XmlRequest = false;
   try {
     XmlRequest = new XMLHttpRequest();
   } catch (trymicrosoft) {
     try {
       XmlRequest = new ActiveXObject("Msxml2.XMLHTTP");
     } catch (othermicrosoft) {
       try {
         XmlRequest = new ActiveXObject("Microsoft.XMLHTTP");
       } catch (failed) {
         XmlRequest = false;
       }  
     }
   }

   if (!XmlRequest)
      alert("对不起，您的浏览器版本过抵不支持 XMLHttpRequest 对象，\n 部分功能可能不能正常使用，请升级您的浏览器!");
    function getCustomerInfo() {
	   //检测合法性
         var username =document.reg.username.value;
         var url = "AccountCheck.asp?action=cusername&username=" + escape(username);
     XmlRequest.open("GET", url, true);
     XmlRequest.onreadystatechange = updatePage;
     XmlRequest.send(null);
   }

   function updatePage() {
	  
   if (XmlRequest.readyState < 4) 
       {
		   document.getElementById("check_username").innerHTML="<img src=../person/images/right.gif width=16 height=16 vspace=0  align=absmiddle hspace=2/>可以注册"
		   }
   if (XmlRequest.readyState == 4)
      { 
         if (XmlRequest.status == 200) 
	          {
                var response = XmlRequest.responseText;
                     document.getElementById("check_username").innerHTML = response;
               } 
                  
      }
 }
function getCustomerInfo1(){
	   var span = document.getElementById('check_username');
    if (document.reg.username.value==""){
 		span.innerHTML='<img src="../person/images/wrong.gif" align="absmiddle" hspace="2"/> <font color=#F26868>用户名不能为空！请继续注册...</font>'
    return false;
 }
  if (document.reg.username.value.length<4 || document.reg.username.value.length>20){
	  span.innerHTML='<img src="../person/images/wrong.gif" align="absmiddle" hspace="2"/> <font color=#F26868>用户名必须是4-20位的字符！请继续注册..</font>'
   return false;
 }
 if (!isStr(document.reg.username.value))
    { 
         span.innerHTML='<img src="../person/images/wrong.gif" align="absmiddle" hspace="2"/> <font color=#F26868>用户名格式错误：英文字母、数字或下划线，4~20个字符、不区分大小写)</font>'
          return false;
    }
 	//如果可以走到这里就调用 AJAX
 	getCustomerInfo();
   }

 function isStr(s) {
	if (s.length == 0) return false;
	//var regu = "^[0-9A-Za-z_]*$";
	var regu = "^[0-9A-Za-z_]*$";
	var re   = new RegExp(regu);
    //alert("ssss---s.search(re):"+s.search(re));
   // s = s.replace('@', '');
    //s = s.replace('.', '');
	if (s.search(re) != -1)
		return true;
 }