var httpRequest;
	
	function cleartxt(){
		document.all.searchtxt.value="";
	}
	
	
function registeruser(){
	location="./register.php";
	//window.open("register.php","title","height=400, width=550");
	
}
function close_login(){
	document.getElementById("logindiv").style.display="none";
}
function open_login(){
	document.getElementById("logindiv").style.display="block";
}
function userlogin(){
	var username=document.all.username_login.value;
	var password=document.all.password_login.value;
	
	var url="./userlogin.php?username="+username+"&&psw="+password;
	createRequest();
	httpRequest.open("Post",url,"true");
	httpRequest.onreadystatechange=loginuser;
	httpRequest.send(null);
	
}
function loginuser(){
		if(httpRequest.readyState==4){
			if(httpRequest.status==200){
					if(httpRequest.responseText==""){
						document.getElementById("errorshow").innerHTML="用户名密码错误";
					}else{
						document.getElementById("logindiv").style.display="none";
						document.getElementById("loginbutton").innerHTML=httpRequest.responseText;
					}
					
					
			}
		}
	}	
	
	function search_mess(){
		var search_str=document.all.searchtxt.value;
		
		if(search_str=="搜索" || search_str==""){
			alert("请输入您要搜索的关键字");
		}else{
			location="./searchmess.php?str="+search_str;
			
		}
	}
	
function createRequest()
	{
	
    try{
     
     httpRequest=new ActiveXObject("Microsoft.XMLHTTP");
	 httpRequest=new XMLHttpRequest();
    }catch(trymicrosoft)
    {
   
        try{
         httpRequest=new ActiveXObject("Msxml2.XMLHTTP");
        }catch(othermicrosoft)
        {
        	
            try{
            
            httpRequest=new XMLHttpRequest();   
            }
            catch(failed)
            {
             httpRequest=false;
            }
        }
    }
    if(!httpRequest)
    {
      
       return null;
    }       
    return httpRequest;
}