jsp+Ajax无刷新验证码

/* namespacing object */ var net=new Object(); net.READY_STATE_UNINITIALIZED=0; net.READY_STATE_LOADING=1; net.READY_STATE_LOADED=2; net.READY_STATE_INTERACTIVE=3; net.READY_STATE_COMPLETE=4; /*--- content loader object for cross-browser requests ---*/ net.ContentLoader=function(url,on_load,on_error,method,params,contentType){ this.req=null; this.on_load=on_load; this.on_error=(on_error) ? on_error : this.defaultError; this.loadXMLDoc(url,method,params,contentType); } net.ContentLoader.prototype.loadXMLDoc=function(url,method,params,contentType){ if (!method) { method="GET"; } if (!contentType && method=="POST") { contentType='application/x-www-form-urlencoded'; } if (window.XMLHttpRequest) { this.req=new XMLHttpRequest(); } else if (window.ActiveXObject) { //add try catch; try { this.req = new ActiveXObject("Msxml2.XMLHTTP"); }catch (e1){ try { this.req = new ActiveXObject("Microsoft.XMLHTTP"); } catch (e2){ } } // //this.req=new ActiveXObject("Microsoft.XMLHTTP"); } if (this.req) { try { var loader=this; this.req.onreadystatechange=function() { net.ContentLoader.onReadyState.call(loader); } this.req.open(method,url,true); if (contentType) { this.req.setRequestHeader('Content-Type', contentType); } this.req.send(params); } catch (err) { this.on_error.call(this); } } } net.ContentLoader.onReadyState=function(){ var req=this.req; var ready=req.readyState; if (ready==net.READY_STATE_COMPLETE){ var httpStatus=req.status; if (httpStatus==200 || httpStatus==0){ this.on_load.call(this); }else{ this.on_error.call(this); } } } net.ContentLoader.prototype.defaultError=function(){ alert("error fetching data!" +"\n\nreadyState:"+this.req.readyState +"\nstatus: "+this.req.status +"\nheaders: "+this.req.getAllResponseHeaders()); }