rem: messenger.openAttachment(url, displayName, messageUri); 
add: messenger.openAttachment(contentType, url, displayName, messageUri); 
context: function OpenAttachURL(url, displayName, messageUri){    var args = {dspname: displayName, opval: 0};  window.openDialog("chrome://messenger/content/openSaveAttachment.xul",                    "openSaveAttachment", "chrome,modal", args);  if (args.opval == 1)      messenger.openAttachment(url, displayName, messageUri);  else if (args.opval == 2)      messenger.saveAttachment(url, displayName, messageUri);}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/cc939ec96c423582a09d1fc93a6d613c7bb32dec/msgHdrViewOverlay.js/clean/mailnews/base/resources/content/msgHdrViewOverlay.js