I am trying to call a centralized server for simple authentication purposes in an intranet environment. Can this be done, or does the call have to be in the same web root?

Thanks for any advice.

Code:
Ext.Ajax.request({
    url: 'http://someserver/webservice/TestService',
    method: 'post',
    params: {
    username: a1ws23,
    password: 'testadm1n'
    },
 
    success: function(response, options) {     
         alert(response.responseText.trim());
    },
 
    failure: function(response, request) {
         alert('Failed - ' + response.status);
    }
});