See this extension: https://addons.mozilla.org/en-US/firefox/addon/s3menu-wizard/

THANK YOU!!!!

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */

#context-sendimage { display:none!important; }

Note that you can also do this with code in userChrome.css without using an extension. Add code to the <b>userChrome.css</b> file below the default @namespace line. *http://kb.mozillazine.org/userChrome.css ---- <pre><nowiki>@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */ #context-sendimage { display:none!important; } </nowiki></pre> ---- The customization files userChrome.css (user interface) and userContent.css (websites) are located in the <b>chrome</b> folder in the Firefox profile folder. *http://kb.mozillazine.org/Editing_configuration You can use this button to go to the current Firefox profile folder: *Help > Troubleshooting Information > Profile Directory:<br>Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder *http://kb.mozillazine.org/Profile_folder_-_Firefox *create the <b>chrome</b> folder (lowercase) in the <xxxxxxxx>.default profile folder if this folder doesn't exist *use a plain text editor like Notepad to create a (new) <b>userChrome.css</b> file in the chrome folder (file name is case sensitive) *paste the code in the userChrome.css file in the editor window *make sure that the userChrome.css file starts with the default <u>@namespace line</u> *Make sure that you select "All files" and not "Text files" when you save the file via "Save file as" in the text editor as userChrome.css.<br>otherwise Windows may add a hidden <i>.txt</i> file extension and you end up with a not working <i>userChrome.css.txt</i> file