ASCII control character html input text

Question

I\'m trying to process input from a barcode scanner in a javascript browser app. The scanner output is a string of characters, which also contains at least one Group Separator c

Answer 1

Firefox doesn't transmit ALT keypress, but only keydown and keyup events.
This work for me in each browser:

//GS1 Datamatrix  in Firefox, Chrome & IE
var altValue = '';
document.getElementById('SKAN').addEventListener('keydown', function(e) {
    if(e.altKey){
        if(e.which != 18){
           altValue += e.which
        }
        if(altValue === '969698105'){
           this.value += String.fromCharCode(29);
        }
    }
});
document.getElementById('SKAN').addEventListener('keyup', function(e) {
    if(e.altKey === false){
      altValue = '';
    }
});