how to activate a textbox if I select an other option in drop down box

Question

suppose I\'ve a 3 options in a drop down box say red , blue, others. If a user select option as an others then below a text box should be visible to wrtie his own favour

Answer 1

This will submit the right form response (i.e. Select value most of the time, and Input value when the Select box is set to "others"). Uses jQuery:

  $("select[name="color"]").change(function(){
    new_value = $(this).val();
    if (new_value == "others") {
      $('input[name="color"]').show();      
    } else {
      $('input[name="color"]').val(new_value);
      $('input[name="color"]').hide();
    }
  });