function checkLogin(pos){
	new Ajax.Request('/function/checkLogin.php',   {method:'get',    parameters: {pos:pos},
   
onSuccess: function(transport){      
 var response = transport.responseText.evalJSON()|| ""; 
var toplogin=document.getElementById('toplogin');
var logindiv=document.getElementById('logindiv');
toplogin.innerHTML = '<div style="width:270px;text-align:right;"><a href="http://www.51zhinao.com/login.php">登陆</a> <a href="http://www.51zhinao.com/reg0.php?type=1">注册</a></div>';
	if(response.string2&&toplogin){
		toplogin.innerHTML=response.string2;
	}
	if(response.string&&logindiv){
		logindiv.innerHTML=response.string;
	}
	if(response.cookievalue){
		var user_mail=document.getElementById('user_mail');
		if(user_mail)user_mail.value=response.cookievalue;
	}
 },     
 onFailure: function(){ alert('Something went wrong...') }   }); 
 return false;
	}
function clearSession(){
	new Ajax.Request('login.php',   {method:'get',    parameters: {action:"logout"},
   
onSuccess: function(transport){      
 
 },     
 onFailure: function(){ alert('Something went wrong...') }   }); 
 return false;
}