var xmlHttp;                        
var userName;                       


function createXmlHttp() {
    
    if (window.XMLHttpRequest) {
       xmlHttp = new XMLHttpRequest();                  
    } else {
       xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
}

//用户发言
function checkuserName111() {
	var RegStr = new RegExp("^[_\.0-9a-z-]+@([0-9a-z][0-9a-z-]+\.)+[a-z]{2,4}$","i") ;
	var userName = document.getElementById("Name").value;

	 if(userName.length>50)
	   {
		document.getElementById('TextUserName').innerHTML = '用户名不能超过！';
		document.getElementById('Name').style.backgroundColor = '#FF0';
		return false;
	   }
	   if( !RegStr.test(userName) )
	   {
		document.getElementById('TextUserName').innerHTML = '请使用您常用的邮箱作为用户名！';
		document.getElementById('Name').style.backgroundColor = '#FF0';
		  return false;
	   }
	 else {
        
        createXmlHttp();                                           
        xmlHttp.onreadystatechange = writeNewMessage;              
        xmlHttp.open("POST", "checkUserName.jsp", true);                 
        xmlHttp.setRequestHeader("Content-type","application/x-www-form-urlencoded");
        xmlHttp.send("action=send" +
                     "&userName=" + encodeURIComponent(userName));                         
    }
}



function writeNewMessage(newMsg) {

    if (xmlHttp.readyState == 4) {
    	
        var msgDiv = document.getElementById('TextUserName');
        var newMsgObj = eval("("+xmlHttp.responseText+")"); 
      
        if (newMsgObj.msg==0) 
        {           
            msgDiv.innerHTML = '恭喜您，您的用户名可以用！';                               	
        }
        if (newMsgObj.msg==1) {
            
            msgDiv.innerHTML = '对不起您的用户名已经存在，请用其他的用户名！';                     
           	
        }
		
      
    }
}


function checkEnter(evt) {
    var code = evt.keyCode||evt.which;  

    
    if (code == 13) {
    	checkuserName();
    }
}