var f = function() {
var s = $(this).val();
var cursorPosition = this.selectionStart;
var lastBacktick = s.indexOf("`", cursorPosition);
var firstBacktick = s.lastIndexOf("`", lastBacktick - 1);
s = s.slice(0, lastBacktick) + s.slice(lastBacktick + 1);
s = s.slice(0, firstBacktick) + s.slice(firstBacktick + 1);
$(this).val(s)
};
$('textarea').on('click', f)