Need to transfer large data (Appox 5MB in the form of XML & HTML) from
Internet Explorer to Web sphere application server. Want to know if
there is anyway I can compress data (JavaScript or otherwise) before
sending it to the server as it takes a long time to do this operation.
I am currently using xmlhttp. Sample code below.	    		
xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
xmlhttp.open("POST",'http://xyz.com',true);
var vSendXML = vMainXMLDOM.xml;//The size of vSendXML is appox 5 MB
xmlhttp.send(vSendXML);

Note: From the server to client I am using GZIP for compression and it
is working pretty good.

If you do it on regular basis you could look for Internet provider
that would give you significantly better 'upload' performance. Some of
them do. Also keeping your XML / HTML markup as short as possible
would descrease the file size and thus the time to transfer.

One option that comes to mind is that you could use a COM compression
library such as the one from http://www.xceedsoft.com. There are a
couple caveats to this solution. 1) This would only work with IE. 2)
You would have to use client side JScript or VBScript. 3) The COM
library would have to be installed on every client using your app. 4)
You would need to configure the IE security settings on each client
accessing your app to allow access to the COM library. If you have
only one, or just a few clients accessing your app, then this may be a
possible alternative.