Access Denied when changing the .src thru javascript

I have thoroughly read many article on the access denied issue regarding disabling Protected Mode thru the preferences and thru the registry. Nothing seems to resolve our current issue.

We embed an Adobe Reader object on a webpage. We give the user the option to navigate to a local pdf and load the file. When I change the .src thru javascript I get an Access Denied error. Tried opening permissions on the local folder, tried running as a system administrator. Nothing seems to allow us to get by this issue.

Code snippet:

        var fileControl = document.getElementById("fUpLoadPDF");
      //alert(fileControl.value);
        ret = CheckIfPDFExtension(fileControl.value);

        if (ret)
        { 
        //alert(document.getElementById("AcroPDF1").src);
            alert(fileControl.value);
             document.getElementById("AcroPDF1").src = fileControl.value;

        }
else {
       alert('Error while checking the file extension');
}

Any help would be appreciated...