function checkForm(){
		var f=document.reg;
   var username=f.nickname;
   var pwd=f.password;
   var repwd=f.password2;
   var Email=f.Email;
   
   if(username.value=="")  //判断用户名
   {
	  alert("IDをご記入ください。");
	  username.focus();
	  return false;
	}else if(document.getElementById("check").innerHTML.indexOf("该用户名已被人使用")!=-1)
	{
	  alert("该用户名已被人使用");
	  username.value='';
	  username.focus();
	  return false;
	}
	if(pwd.value=="") //判断密码
	{
	  alert("密码不能为空！");
	  pwd.focus();
	  return false;
		}else if(pwd.value.length<6 || pwd.value.length>16){
			alert("密码长度为6~16位！");
	 		 pwd.value='';
	 		 pwd.focus();
	 		 return false;
			}
	if (repwd.value==""){ //确认密码
          alert("请再输入一次密码！");
          repwd.focus();
          return false;
        }else if(pwd.value!=repwd.value){
				alert("两次输入的密码不一致！");
				 repwd.value='';
				 repwd.focus();
				 return false;
			}
	
	if(Email.value=="")//判断邮箱
	{
	  alert("Email不能为空");
	  Email.focus();
	  return false;
		}else if(!(Email.value.indexOf('@')>=0&&Email.value.indexOf('.')>=0&&Email.value.indexOf('.')>Email.value.indexOf('@')+1))
	{
		alert("您的邮箱不合法！");
		Email.value='';
		Email.focus();
		return false;
	}
}