var httpRequest;
    function vaildateuser(username)
	{
		if(username!=""){
			
			var url="./validateuser.php?username="+username;
			createRequest();
			httpRequest.open("Post",url,"true");
			httpRequest.onreadystatechange=validateus;
			httpRequest.send(null);
		}
		
	}
	function vaildate_psw(two_psw){
		var one_psw=document.all.passwords.value;
		if(one_psw!=two_psw){
			alert("密码不相符请查实修改");
			document.all.password.value="";
			document.all.againpassword.value="";
		}else{
			document.all.comits.disabled="";
		}
	}
	function validateus(){
		if(httpRequest.readyState==4){
			if(httpRequest.status==200){
					document.getElementById("imgshow").innerHTML=httpRequest.responseText;
			}
		}
	}	
	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;
}