/src/main/java/org/htmlunit/html/HtmlSelect.java
lastSelectedIndex_ = getOptions ( ) .indexOf ( selectedOption ) ;
final boolean isSelected, final boolean shiftKey, final boolean ctrlKey, final boolean isClick) { if (isMultipleSelectEnabled()) { selectedOption.setSelectedInternal(isSelected); if (isClick && !ctrlKey) { if (!shiftKey) { setOnlySelected(selectedOption, isSelected); <extra_id_0> } else if (isSelected && lastSelectedIndex_ != -1) { final List<HtmlOption> options = getOptions(); final int newIndex = options.indexOf(selectedOption); for (int i = 0; i < options.size(); i++) { options.get(i).setSelectedInternal(isBetween(i, lastSelectedIndex_, newIndex));