Asynchronous Data submission using JavaScript (Ajax) (original)

Using JavaScript for asynchronous data submission is much more efficient than directly using the ready-made Ajax control (I have only used ajax.net)
The experiment found that large data could be submitted-about 40 kb of Experiment
Function dosubmit ()
{
.......
VaR urlparameter = "cfg =" + urlpara1
+ "& Type =" + vkeytype
+ "& Starttime =" + vstarttime
+ "& Endtime =" + vendtime
+ "& Subject =" + vsubject;
// Alert (vsubject );
// Return;

If (typeof XMLHttpRequest! = 'Undefined ')
{
Httprequest3 = new XMLHttpRequest ();
}
Else if (typeof activexobject! = 'Undefined ')
{
Httprequest3 = new activexobject ('Microsoft. xmlhttp ');
}
If (httprequest3)
{
Httprequest3.open ('post', "/background page. aspx", true); // true is asynchronous
Httprequest3.setrequestheader ('content-type', 'application/X-WWW-form-urlencoded ');
Httprequest3.onreadystatechange = oncomplete;
Httprequest3.send (urlparameter );
}

Currentpage = N;
Return;
}
Function oncomplete ()
{
If (4 = httprequest3.readystate)
{
// Alert (httprequest3.responsetext );
If (200 = httprequest3.status)
{
VaR rettext = httprequest3.responsetext;
Document. getelementbyid ("mainlist"). innerhtml = rettext;
}
}
}