Ajax function code for beginners

Time:2021-12-7
Copy codeThe code is as follows:
/*
Call method:
1. Post mode
var txt = escape(sender.value); //document.getElementById(“<%= txtName.ClientID %>”).value);
var data = “name=” + txt + “&pwd=” + txt;
var option = { “url”: “handler/Handler.ashx”
, “action”: “POST”
, “callback”: function(){
If (xmlhttp. ReadyState = = 4) {/ / the server responded
If (xmlhttp. Status = = 200) {/ / the service responds correctly
alert(xmlHttp.responseText);
}
xmlHttp = null; // Recycling resources
}
   }
, “data”: data
};
ajax(option);
2. Get mode
var txt = escape(sender.value); //document.getElementById(“<%= txtName.ClientID %>”).value);
var option = { “url”: “handler/Handler.ashx&name=” + txt + “&pwd=” + txt
, “action”: “POST”
, “callback”: function(){
If (xmlhttp. ReadyState = = 4) {/ / the server responded
If (xmlhttp. Status = = 200) {/ / the service responds correctly
alert(xmlHttp.responseText);
}
xmlHttp = null; // Recycling resources
}
   }
};
ajax(option);
*/
function ajax(option) {
createXMlHttpRequest(); // Create XMLHttpRequest object
if (option != null && option != undefined) {
if (option.url == null && option.url == undefined) {
xmlHttp = null;
Alert (“missing required parameter option. URL”);
return;
}
if (option.action == null && option.action == undefined) {
xmlHttp = null;
Alert (“missing required parameter option. Action”);
return;
}
xmlHttp.open(option.action, option.url, true);
if (option.contentType != null && option.contentType != undefined) {
xmlHttp.setRequestHeader(“Content-Type”, option.contentType);
} else {
xmlHttp.setRequestHeader(“Content-Type”, “application/x-www-form-urlencoded”);
}
if (option.callback != null && option.callback != undefined) {
xmlHttp.onreadystatechange = option.callback;
}
if (option.action.toUpperCase() == “POST”) {
xmlHttp.send(option.data);
} else {
xmlHttp.send(null);
}
}
}
var xmlHttp; // After the call is completed, you’d better recycle xmlhttp = null;
/*Get element*/
function g(arg) {
var t = document.getElementById(arg);
if (null != t && t != undefined) {
return t;
}
t = document.getElementsByName(arg);
if (null != t && t != undefined) {
return t;
}
t = document.getElementsByTagName(arg);
if (null != t && t != undefined) {
return t;
}
}
/*Create an Ajax request object*/
function createXMlHttpRequest() {
try {//Firefox, Chrome, Surfri, Opera+8
xmlHttp = new XMLHttpRequest();
}
catch (ie) {
try {//IE6+
xmlHttp = new ActiveXObject(“Msxml2.XMLHTTP”);
} catch (ie) {
xmlHttp = new ActiveXObject(“Microsoft.XMLHTTP”);
}
}
return xmlHttp;
}