Javascript to call Web Service

I'm trying to call a web service using javascript.  I am doing this as a solution to a user disabling ActiveX in IE 6.  I have already created my own version of the IFrame 'hack' to implement AJAX calls to a page when ActiveX is disabled, but I now want to call a web service rather than an aspx page.  Can somebody tell me how to call a web service without using the XMLHttpRequest object.  I don't want to continue to create pages to do the work of web services.  Eventually I will no longer support IE 6 and will want everything to use web services.  Any help is greatly appreciated.

 Thanks,

 Ryan
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