                javascript: function () {
                    var str, j = i, e;

                    if (input.charAt(j) === '~') { j++; e = true; } // Escaped strings
                    if (input.charAt(j) !== '`') { return; }
                    if (env.javascriptEnabled !== undefined && !env.javascriptEnabled) {
                        error("You are using JavaScript, which has been disabled.");
                    }

                    if (e) { $char('~'); }

                    str = $re(/^`([^`]*)`/);
                    if (str) {
                        return new(tree.JavaScript)(str[1], i, e);
                    }
                }
The software constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.