Code to post and receive XML from System-Link

Hi All,
My customer requires me to use ASP to post a request to XML, get the XML from 
System Link and display the page by transforming or parsing the XML Reponse 
given by System Link.
I am able to get the XML Request from PowerLink and I am able to use the 
Simulator to post the request to the System link and get the XML output. 
The issue is the XML returned either gets displayed in a separate window, 
which I am not able to process in code 
(or) 
I am able to get the code into an IFrame, using which I cannot get the XML 
from IFrame as IE does not allow it.

I tried to use XML HTTP Posting, but the variable SystemLinkRequest variable 
and the value is not recognized by system-link, when I post it through XML 
HTTP object.
This is the code for XML HTTP 
function GetXML()
{
var ctr = 0;
var xmlRequest = new ActiveXObject("Microsoft.XMLDOM");
var xslTemplate = new ActiveXObject("Microsoft.XMLDOM");
var xmlResponse = new ActiveXObject("Microsoft.XMLDOM");
var objXmlHttp = new ActiveXObject("Microsoft.XMLHTTP");

strRequest = "<?xml version='1.0'?> \n <!DOCTYPE System-Link 
SYSTEM 'SystemLinkRequest.dtd'> <System-Link> <Login userId='login' 
password='pwd' maxIdle='900000' 
properties='com.mapics.cas.domain.EnvironmentId=TT, 
com.mapics.cas.domain.SystemName=dev.domain.com, 
com.mapics.cas.user.LanguageId=en'/> <Request sessionHandle='*current' 
workHandle='*new' broker='EJB' maxIdle='1000'> <QueryList 
name='queryListCustomer_General' domainClass='com.mapics.csm.Customer' 
includeMetaData='true' maxReturned='50'> <Pql> <![CDATA[SELECT 
company,customer,addresseeName,city,contact,telephone,fax,currency,customerStat
us,customerClass,territory,salesrep where addresseeName like 'abc%' ORDER BY 
company,customer]]> </Pql> </QueryList> </Request> </System-Link>";
        
objXmlHttp.open
("POST","http://dev:36001/SystemLink/servlet/SystemLinkServlet/",false);
objXmlHttp.setRequestHeader ("Content-Type", "application/xml") ;
objXmlHttp.send('SystemLinkRequest="' + strRequest + '"');
xslTemplate.async = false;
xslTemplate.load("Basic.xsl");
document.getElementById("responseFrame").document.innerHTML = 
objXmlHttp.responseText;
}

I am getting a response as HTTP ERROR: 500 URLDecoder%
3A+Illegal+hex+characters+in+escape+%28%25%29+pattern+%2D+For+input+string%3A+%
22%27+%22


Could somebody point me to the right place or provide me with some code of how 
to resolve it. I need to do more with it of updating and deletion and finally 
use MAPICS as base for all the transactions directly from the WEB.

Advanced Thanks for anyone who could provide me with information