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ASCII Control Codes Keyboard Input Helper for Firefox
This is a script to help inputting ASCII Control Codes such as TAB, CR, LF, etc. on Firefox web browsers using ALT+Numpad keys. Inputted control codes must begin with 0 (e.g. 09, 013, etc.), and only control code 1 to 31 are accepted. The control character will only be generated when the current focus is on a TEXTAREA element, or a text typed INPUT element.