function ck_reg()
{
var fn=document.reg;
if(!fn.username.value){alert('請輸入用戶名。');return false;}
if(document.getElementById('username_c').innerHTML){alert('請檢查用戶名。');return false;}
if(!fn.userpwd.value){alert('請輸入用戶密碼。');return false;}
if(fn.userpwd.value!=fn.re_userpwd.value){alert('密碼與確認密碼不一致。');return false;}
if(!fn.useremail.value){alert('請輸入您的電子郵箱。');return false;}



var emailfilter=/^\w+[\+\.\w-]*@([\w-]+\.)*\w+[\w-]*\.([a-z]{2,4}|\d+)$/i ;
if(fn.useremail.value){
var returnval=emailfilter.test(fn.useremail.value);
if (returnval==false){alert('請檢查電子郵件是否有誤！');fn.useremail.focus();return false;} 
}
if(!fn.cname.value){alert('請輸入您的姓名(聯絡人)');return false;}
if(!fn.tel.value&&!fn.tel2.value){alert('請輸入您的聯絡手機或住宅電話。');return false;}
fn.action='reg.php?action=add';
}
var   xmlHttp; 
function   createXMLHttpRequest()   {   
if   (window.ActiveXObject)   {   
xmlHttp   =   new   ActiveXObject("Microsoft.XMLHTTP");   
}     
else   if   (window.XMLHttpRequest)   {   
xmlHttp   =   new   XMLHttpRequest();   
}   
}     
function  return_username()   {   
if(xmlHttp.readyState   ==   4)   {  	
if(xmlHttp.status   ==   200)   { 

document.getElementById('username_c').innerHTML=xmlHttp.responseText;


}}}   
		
function ck_username(username){
createXMLHttpRequest();   
xmlHttp.onreadystatechange   =  return_username;   
xmlHttp.open("GET",   "reg_ck.php?username="+username,   true);   
xmlHttp.send(null);   
}