function checkform(){ 
if (form1.name.value==""){ 
alert("Please enter your name."); 
document.getElementById("name").focus(); 
return(false); 
} 

if (form1.name.value=="  "){ 
alert("Incorrect name entry, please fill in again."); 
document.getElementById("name").focus(); 
return(false); 
} 

if (form1.sex.value==""){ 
alert("Please enter your gender."); 
document.getElementById("sex").focus(); 
return(false); 
} 

if (form1.birth_country.value==""){ 
alert("Please enter your country."); 
document.getElementById("birth_country").focus(); 
return(false); 
} 

if (form1.address.value==""){ 
alert("Please enter your address."); 
document.getElementById("address").focus(); 
return(false); 
} 　

if (form1.city1.value==""){ 
alert("Please enter your city."); 
document.getElementById("city1").focus(); 
return(false); 
} 

if (form1.birth_state.value==""){ 
alert("Please enter your State/Province."); 
document.getElementById("birth_state").focus(); 
return(false); 
} 

if (form1.postalcode.value==""){ 
alert("Please enter your postal code."); 
document.getElementById("postalcode").focus(); 
return(false); 
} 
//postalcode 格式
if(isNaN(form1.postalcode.value)==true) 
   {     
   alert("Incorrect postalcode format, please re-enter."); 
   document.getElementById("postalcode").focus();     
   return(false);     
  }
  
 if (form1.phone.value==""){ 
alert("Please enter your phone number."); 
document.getElementById("phone").focus(); 
return(false); 
} 　

//Phone 格式
var filter1 =/^((\+)*(\s)*(\d)+(\s)*(\d)*(\+)*(-)*)+$/;

   if   (!filter1.test(form1.phone.value))
{   
   alert("Incorrect phone format, please re-enter."); 
   document.getElementById("phone").focus();     
   return(false);     
  }
  
if (form1.email.value==""){ 
alert("Please enter email address."); 
document.getElementById("email").focus(); 
return(false); 
}
 
if (form1.checkemail.value==""){ 
alert("Please re-enter email address."); 
document.getElementById("checkemail").focus(); 
return(false); 
} 
//判断两次email是否一致
if(form1.email.value!=form1.checkemail.value){
alert("Two different email address, please re-enter."); 
document.getElementById("email").focus(); 
form1.email.value="";
form1.checkemail.value="";
return(false);
}   

//正则判断email格式 
var   filter=/^\s*([A-Za-z0-9_-]+(\.\w+)*@(\w+\.)+\w{2,3})\s*$/;   
  if   (!filter.test(form1.email.value))   
  {     
   alert("Incorrect email format, please re-enter."); 
   document.getElementById("email").focus();     
              return   false;     
  }  

if (form1.username.value==""){ 
alert("Please choose a username."); 
document.getElementById("username").focus(); 
return(false); 
}  
//判断用户名字长度
if (form1.username.value.length<4){ 
alert("Four characters minimum for username! Please re-create."); 
document.getElementById("username").focus(); 
return(false); 
} 
if (form1.username.value.length>20){ 
alert("20 characters Max for username! Please re-create."); 
document.getElementById("username").focus(); 
return(false); 
} 
if (form1.validname.value=="0"){ 
alert("Please choose another username."); 
document.getElementById("username").focus(); 
return(false); 
}
// username must be lowercase or number
var   filter1=/^[a-z0-9]+$/;
  if   (!filter1.test(form1.username.value))   
  {     
   alert("Please use number or lowercase letter."); 
   document.getElementById("username").focus();
   return   false;     
  }  
if (form1.password.value==""){ 
alert("Please choose a password."); 
document.getElementById("password").focus(); 
return(false); 
}
//判断密码位数
if(form1.password.value.length<6) {
alert("Six characters minimum for password! Please re-create."); 
document.getElementById("password").focus(); 
return(false); 
}

if (form1.makesure.value==""){ 
alert("Please re-enter password."); 
document.getElementById("makesure").focus(); 
return(false); 
}

//判断密码是否一致
if(form1.password.value!=form1.makesure.value){
alert("Two different email addresses, please fill in again."); 
document.getElementById("password").focus(); 
form1.password.value="";
form1.makesure.value="";
return(false);
} 

if (form1.question.selectedIndex <= 0){ 
alert("Please select your secret question."); 
document.getElementById("question").focus(); 
return(false); 
}

if (form1.answer.value==""){ 
alert("Please choose your secret answer."); 
document.getElementById("answer").focus(); 
return(false); 
}

if (form1.checkbox.checked!=true)
  { 
alert("Please read the Merchant Agreement and the Private Policy, and select accept, then submit your registration."); 
document.getElementById("checkbox").focus(); 
return(false); 
  } 
}