how to use more than one external web service in a single project.
You can refer multiple webservices at one time. There is no limitation on the same. Add multiple web references to your web project - use right click option on the web app project - this will automatically make changes to your web.config once you add new reference.
how to use once in one time.
Create an object of the webservice in need and call the methods of that webservice. There will be no issue or conflict with other one(s). All will be independent and object based.
in case you don't know how to add web reference, look here:
How to make a simple WebService and consume it.[
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