Calling Services using ASP.Net AJAX Website

Can we create a ASP.Net AJAX based Website to call

1. Internal WebService

2. External Web Service

3. Internal WCF Service

4. External WCF Service

5. Internal AJAX based WCF Service

6. External AJAX based WCF Service.

 Please help me by refering some examples.

Thanks in Advance

Mohan G
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