$('select').change(function() {

  reEvaluateAvailableOptions();

});

​

function reEvaluateAvailableOptions() {

  var selectElements = $('#select1, #select2,#select3, #select4, #select5');

​

  var selectedValues = [];

  selectElements.each(function() {

    var value = $(this).val();

​

    value >= 0 && selectedValues.push(value);

  });

​

  // Disable all the selected values.

  selectElements.each(function() {

    var currentValue = $(this).val();

​

​

    $(this).children('option')

      .removeAttr("disabled")

      .each(function() {

​

        var value = this.value;

        if (selectedValues.indexOf(value) >= 0 && currentValue != value) {

          $(this).attr('disabled', "disabled");

        }

      });

  });

}