removing all options of select box except 1st option

Question

I\'m trying to empty select options when:

id \"mClick\" is selected, id\'s \"sClick\", \"cClick\" and \"srClick\" will be emptied.

id \"sClick\" is selected,

Answer 1

The easiest way to clear the options in the way you're describing is by using options.length = 1. Also, you can leverage the fact that each drop down clears the ones that logically follow it, so that you only need to declare a single change handler.

$('#lForm select').on('change', function() {
  if (this.selectedIndex > 0) {
    var $others = $(this).closest('table').find('select'),
    current = $others.index(this); // find current

    while (++current < $others.length) {
      // for each following drop down
      $others.get(current).options.length = 1;
    }
  }
});

Demo

I'm not sure how you're going to repopulate the drop downs though :)