Connect to a Secure webservice with Client Certificate

HI,Hoping someone can help.

 We have a web application developed in ASP.NET VB.  We are using a third party that provides data for our use in XML via a secure URL.

 I am using XMLReader to read the XML, and works fine on a local test file.  However I can't get it to use the live data as I cannot connect securely.  The error is :System.Net.WebException: The request was aborted: Could not create SSL/TLS secure channel.


 I need to use a client certificate (which we have) to access the XML via a URL.   Unfortunately I dont know where to start to code this and hoping someone can point me in the right direction, help with steps required or an example of something similar.

We are using ASP.NET 2.0, My test machine is IIS 7. 

 Thanks

Eric
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