function check_reg()
{
	if($('username').value == "")
	{
		alert('用户名不可为空！');
		$('username').focus();
		return false;
	}
	else if(!checkLen($('username').value,4,20))
	{
		alert('用户名长度不合适！');
		$('username').focus();
		return false;
	}
	if($('nickname').value == "")
	{
		alert('用户昵称不可为空！');
		$('nickname').focus();
		return false;
	}
	else if(!checkLen($('nickname').value,2,20))
	{
		alert('用户昵称长度不合适！');
		$('nickname').focus();
		return false;
	}
	if($('email').value == "")
	{
		alert('邮箱不可为空！');
		$('email').focus();
		return false;
	}
	else if(!checkEmail($('email').value))
	{
		alert('邮箱格式不正确！');
		$('email').focus();
		return false;
	}
	if($('password').value == "")
	{
		alert('密码不可为空！');
		$('password').focus();
		return false;
	}
	else if(!checkLen($('password').value,6,20))
	{
		alert('密码长度不合适！');
		$('password').focus();
		return false;
	}
	if($('password').value != $('password_ack').value)
	{
		alert('两次密码不一致！');
		$('password').value = '';
		$('password_ack').value = '';
		$('password').focus();
		return false;
	}
}


//检查是否含有除数字英文外的字符
function checkname(str)
{
	var re = new RegExp("^[A-za-z0-9]+$","g");
	return re.test(str);
}

function check_username()
{
	var username = $('username').value;
	if(username == "")
	{
		document.getElementById('checkusername').innerHTML = '<span class="regspan8_1">不可为空</span>';
		return false;
	}
	else if(!checkLen(username,4,20))
	{
		document.getElementById('checkusername').innerHTML = '<span class="regspan8_1">长度不对</span>';
		return false;
	}
	else if(!checkname(username))
	{
		document.getElementById('checkusername').innerHTML = '<span class="regspan8_1">格式不对</span>';
		return false;
	}
	else
	{
		ajax = createXMLHttpRequest();
		ajax.open("GET","includes/checkuser.php?work=name&key=" + username,true);
		ajax.onreadystatechange = loadingName;
		ajax.setRequestHeader("If-Modified-Since","0");
		ajax.send(null);
	}
	return true;
}

function loadingName()
{
	if(ajax.readyState==4)
	{
		if(ajax.status==200)
		{
			document.getElementById('checkusername').innerHTML = ajax.responseText;
		}
		else
		{
			alert('对不起，读取数据出错了');
		}
	}	
}

function check_nickname()
{
	var nickname = $('nickname').value;
	if(nickname == "")
	{
		document.getElementById('checknickname').innerHTML = '<span class="regspan8_1">不可为空</span>';
		return false;
	}
	else if(!checkLen(nickname,2,20))
	{
		document.getElementById('checknickname').innerHTML = '<span class="regspan8_1">长度不对</span>';
		return false;
	}
	else
	{
		ajax = createXMLHttpRequest();
		ajax.open("GET","includes/checkuser.php?work=nickname&key=" + nickname,true);
		ajax.onreadystatechange = loadingNickName;
		ajax.setRequestHeader("If-Modified-Since","0");
		ajax.send(null);
	}
	return true;
}

function loadingNickName()
{
	if(ajax.readyState==4)
	{
		if(ajax.status==200)
		{
			document.getElementById('checknickname').innerHTML = ajax.responseText;
		}
		else
		{
			alert('对不起，读取数据出错了');
		}
	}	
}

function check_email()
{
	var email = $('email').value;
	if(email == "")
	{
		document.getElementById('checkemail').innerHTML = '<span class="regspan8_1">不可为空</span>';
		return false;
	}
	else if(!checkEmail(email))
	{
		document.getElementById('checkemail').innerHTML = '<span class="regspan8_1">格式错误</span>';
		return false;
	}
	else
	{
		ajax = createXMLHttpRequest();
		ajax.open("GET","includes/checkuser.php?work=email&key=" + email,true);
		ajax.onreadystatechange = loadingEmail;
		ajax.setRequestHeader("If-Modified-Since","0");
		ajax.send(null);
	}
	return true;
}

function loadingEmail()
{
	if(ajax.readyState==4)
	{
		if(ajax.status==200)
		{
			document.getElementById('checkemail').innerHTML = ajax.responseText;
		}
		else
		{
			alert('对不起，读取数据出错了');
		}
	}	
}

function check_pwd()
{
	var pwd = $('password').value;
	if(pwd == "")
	{
		document.getElementById('checkpwd').innerHTML = '<span class="regspan8_1">不可为空</span>';
		return false;
	}
	else if(!checkLen(pwd,6,20))
	{
		document.getElementById('checkpwd').innerHTML = '<span class="regspan8_1">长度不对</span>';
		return false;
	}
	else
	{
		document.getElementById('checkpwd').innerHTML = '<span class="regspan8">正确</span>';
		return true;
	}
}
function check_pwd2()
{
	var pwd = $('password').value;
	var pwd2 = $('password_ack').value;
	if(pwd2 == "")
	{
		document.getElementById('checkpwd2').innerHTML = '<span class="regspan8_1">不可为空</span>';
		return false;
	}
	else if(pwd2 != pwd)
	{
		document.getElementById('checkpwd2').innerHTML = '<span class="regspan8_1">密码不一致</span>';
		return false;
	}
	else
	{
		document.getElementById('checkpwd2').innerHTML = '<span class="regspan8">正确</span>';
		return true;
	}
}



function checkLen(str,min,max)
{
	var s_re=true;
	if (max>0)
	{
		if (str.length>max)
		{
			s_re=false;
		}
	}
	if (str.length<min)
	{
		s_re=false;
	}
	return s_re;
}
function checkEmail(str)
{
	var patrn=/^[\w-]+(\.[\w-]+)*@[\w-]+(\.[\w-]+)+$/;  
	if (!patrn.exec(str))
	{
		return false;
	}else{
		return true;
	}
}