Ajax最简单例子Demo

Ajax最简单例子，一个例子让你明白Ajax原理，XMLHttpRequest原理varhttp_request=false;functioncreateRequest(url){http_request=false;if(window.XMLHttpRequest){//Mozilla浏览器http_request=newXMLHttpRequest();if(http_request.overrideMimeType){http_request.overrideMimeType(