var username_empty = "Username is required.";
        var username_shorter = "Mininum length of username is three.";
        var username_invalid = "English letters, numbers and underline used for username only.";
        var password_empty = "Password is required.";
        var password_shorter = "Mininum length of password is six.";
         var confirm_password_invalid = "Passwords not matched";

        var email_empty = "Email address is required.";



        var email_invalid = "Invalid Email address";


function reg()
{

  var frm  = document.forms['formUser'];
  // alert("sss");
  var username  =(frm.elements['username'].value);
  // alert("sss2");
  var email  = (frm.elements['email'].value);
  // alert("sss3");
  var password  = (frm.elements['pass'].value);
  // alert("sss31");
  var confirm_password =(frm.elements['cpass'].value);
  // alert("sss32");
  var msg = "";
  // 检查输入
  var msg = '';
 
   if (email.length == 0)
  {
    msg += email_empty + '\n';
  }
  else  
  {
       var regmm = /([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)/;
       var ismail  = false;
	   ismail=regmm.test( email )
	   if (ismail==false)
	   {
	     // msg += email_invalid + '\n';
	   }
  }
  
  if (username.length == 0)
  {
    msg += username_empty + '\n';
  } 
  else if (username.match(/^\s*$|^c:\\con\\con$|[%,\'\*\"\s\t\<\>\&\\]/))
  {
    msg += username_invalid + '\n';
  }
  else if (username.length < 3)
  {
    msg += username_shorter + '\n';
  }

  if (password.length == 0)
  {
    msg += password_empty + '\n';
  }
  else if (password.length < 6)
  {
    msg += password_shorter + '\n';
  }
  if (confirm_password != password )
  {
    msg += confirm_password_invalid + '\n';
  }

  if (msg.length > 0)
  {
    alert(msg);
    return false;
  }
  else
  {
    return true;
  }
}

function showDiv(){
document.getElementById('popDiv').style.display='block';
document.getElementById('bg').style.display='block';
document.getElementById('reg').style.display='none';
}

function showDiv2(){
document.getElementById('reg').style.display='block';
document.getElementById('popDiv').style.display='none';
document.getElementById('bg').style.display='block';
}

function closeDiv(){
document.getElementById('popDiv').style.display='none';
document.getElementById('bg').style.display='none';
document.getElementById('reg').style.display='none';
}