Using PowerShell to query CRM 2011 SOAP endpoint – help!

I don’t know what I am doing wrong. All I am trying to do is to query  CRM 2011 via PowerShell and SOAP. The following PowerShell script should return the Contact’s full name, but I get nothing. Any ideas??

Here is the PowerShell:

$xml = "<?xml version='1.0' encoding='utf-8'?>"
$xml += "<soap:Envelope xmlns:soap='http://schemas.xmlsoap.org/soap/envelope/' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xmlns:xsd='http://www.w3.org/2001/XMLSchema'>"
$xml += "<soap:Body>"
$xml += "<Retrieve xmlns='http://schemas.microsoft.com/xrm/2011/Contracts/Services'>"
$xml += "<entityName>contact</entityName>"
$xml += "<id>12345678-1234-1234-1234-123456789012</id>"
$xml += "<columnSet xmlns:q1='http://schemas.microsoft.com/xrm/2011/Contracts' xsi:type='q1:ColumnSet'>"
$xml += "<q1:Attributes>"
$xml += "<q1:Attribute>fullname</q1:Attribute>"
$xml += "<q1:Attribute>telephone1</q1:Attribute>"
$xml += "</q1:Attributes>"
$xml += "</columnSet>"
$xml += "</Retrieve></soap:Body></soap:Envelope>"

$url="http://crmserver.company.com/Organization/XRMServices/2011/Organization.svc/web"
$http_request = New-Object -ComObject Msxml2.XMLHTTP
$http_request.Open('POST', $url, $false)
$http_request.setRequestHeader("SOAPAction", "http://schemas.microsoft.com/xrm/2011/Contracts/Services/IOrganizationService/Retrieve");
$http_request.setRequestHeader("Content-Type", "text/xml; charset=utf-8");
$http_request.setRequestHeader("Content-Length", $xml.length);
$http_request.send($xml);
$http_request.responseText

And here is the response:

$http_request.responseText

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
<s:Body><RetrieveResponse xmlns="http://schemas.microsoft.com/xrm/2011/Contracts/Services">
<RetrieveResult xmlns:a="http://schemas.microsoft.com/xrm/2011/Contracts" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<a:Attributes xmlns:b="http://schemas.datacontract.org/2004/07/System.Collections.Generic">
<a:KeyValuePairOfstringanyType>
<b:key>accountid</b:key>
<b:value i:type="c:guid" xmlns:c="http://schemas.microsoft.com/2003/10/Serialization/">12345678-1234-1234-1234-123456789012</b:value>
</a:KeyValuePairOfstringanyType>
</a:Attributes>
<a:EntityState i:nil="true"/><a:FormattedValues xmlns:b="http://schemas.datacontract.org/2004/07/System.Collections.Generic"/>
<a:Id>12345678-1234-1234-1234-123456789012</a:Id><a:LogicalName>account</a:LogicalName>
<a:RelatedEntities xmlns:b="http://schemas.datacontract.org/2004/07/System.Collections.Generic"/>
</RetrieveResult>
</RetrieveResponse>

I just don’t know what I am doing wrong. Why won’t the code return “fullname”, it is in the columnSet.

Update-2012-05-08:I have posted my question here, no answer yet

Update2-2012-05-05: I have posted and received and answer here on stack overflow. Big thanks to @JLattimer