Basic Authentication with jQuery.ajax request and jsonp

I have some local html/js files with which I'd like to invoke some remote servers via https and eventually use Basic Authentication for the request.

I am encountering two problems. First is that if I don't specify 'jsonp' for the dataType, jQuery.ajax() request returns the error:

Access to restricted URI denied code: 1012

Are my requests considered cross-domain because my main work file is stored locally, but retrieving data from a server elsewhere?

So fine, I update the call so it now looks like:

$.ajax({ 
     url: myServerUrl,
     type: "GET", 
     dataType: "jsonp", // considered a cross domain Ajax request if not specified
     username: myUsername,
     password: myPassword,

     success: function(result)
     {
        // success handling
     },
     error: function(req, status, errThrown){
         // error handling
     }
})

Because I need to use Basic Authentication, I'm passing in the username/password but if I monitor the request, I don't see it being set and additionally, the server sends an error response since it doesn't have the expected info.

Additionally, because I have jsonp set, beforeSend won't get invoked.

How do I pass along the credentials using Basic Authentication for this request?