Php+ajax implementation of User login verification problem solving?

form in the user name and password two properties, click the button trigger Ajax function, this AJAX function extracts the form "User name" and "password" value sent to the background program verification, PHP writing background program, PHP program for "User name" and "password" to verify, user name error to give a hint, Back to Ajax, display in, the same password error, displayed in, now the user name and password can be correctly uploaded to the PHP program, to make the correct verification, but Xmlhttp.responsetext, how to achieve the above effect? Urgent!!!

Reply to discussion (solution)

Post your code!

You need to assign a conditional value to a different target in the callback function, then return the control information.

//JavaScript documentvar xmlhttp;function s_xmlhttprequest () {if (window. Activxobject) {xmlhttp=new activexobject (' mcrosoft.xmlhttp ');} else if (window. XMLHttpRequest) {xmlhttp=new XMLHttpRequest;}}   function php100 () {s_xmlhttprequest (); user=document.myform.user.value;pwd=document.myform.pwd.value; var poststr = ' user= ' + user+ ' &pwd= ' +pwd;xmlhttp.open (' POST ', ' login3.php ', true); Defines the transmitted file HTTP header information Xmlhttp.onreadystatechange=byphp;xmlhttp.setrequestheader (' Content-type ', ' application/ X-www-form-urlencoded '); Send post Data xmlhttp.send (POSTSTR);} function byphp () {var Byphp100=xmlhttp.responsetext;document.getelementbyid (' UserInfo '). innerhtml=byphp100;} JavaScript document//JavaScript Document 

Form Name= "MyForm" method= "POST" action= "" > User name:   
Password   

The information returned by the user name validation is displayed in the UserInfo Div, and the password is displayed in the Passinfo div; How should the code be changed? Hope to be more detailed, novice Thank you!

You don't have a callback.

var Byphp100=xmlhttp.responsetext;
document.getElementById (' UserInfo '). innerhtml=byphp100; Is this not a callback process?

function byphp () {  var byphp100=xmlhttp.responsetext;  if (/user/.test (byphp100))    document.getElementById (' UserInfo '). innerhtml=byphp100;  else    document.getElementById (' Passinfo '). innerhtml=byphp100;}

Index.html





Untitled Document




User name:

Password

Ajax.js
var http_request;
function Send_request (Url,method) {
Http_request = false;
if (window. XMLHttpRequest) {
Http_request = new XMLHttpRequest ();
if (Http_request.overridemimetype) {
Http_request.overridemimetype (' Text/xml ');
}
}
else if (window. ActiveXObject) {
try {
Http_request = new ActiveXObject ("Msxml2.xmlhttp");
} catch (e) {
try {
Http_request = new ActiveXObject ("Microsoft.XMLHTTP");
} catch (e) {}
}
}
if (!http_request) {
Window.alert ("Cannot create XMLHttpRequest object instance.");
return false;
}
Switch (method) {
Case 1:http_request.onreadystatechange = Chk;break;
}
Http_request.open ("GET", url, True);
Http_request.send (NULL);
}

function Check () {
Send_request ("check.php?action=" +document.getelementbyid (' pw '). value,1);


function Chk () {
if (http_request.readystate = = 4) {
if (Http_request.status = = 200) {
document.getElementById ("User"). innerhtml= "";
document.getElementById ("User"). Value=http_request.responsetext;
} else {
Alert ("The page exception that you requested. ");
}
}else {
document.getElementById ("User"). innerhtml= "reading data ...";
}
}


check.php


if (exists) {
echo "Right";
}else{
Echo is "not correct";
}
?>

check.php $_post[' username ' and $_post[' PW ']

function byphp () {  var byphp100=xmlhttp.responsetext;  if (/user/.test (byphp100))    document.getElementById (' UserInfo '). innerhtml=byphp100;  else    document.getElementById (' Passinfo '). innerhtml=byphp100;}

Code to run, I still can not display the "User name" and "password" verification return information into different div? How does the callback control information be written? Thank you! --Novice!

Pass the JSON.

Remembered! Isn't it better to use jquery?

