$.fn.clearSelect = function() {
    return this.each(function() {
        if (this.tagName == 'SELECT')
            this.options.length = 0;
    });
 }

 $.fn.fillSelect = function(data) {
     return this.clearSelect().each(function() {
         if (this.tagName == 'SELECT') {
             var dropdownList = this;
             $.each(data, function(index, optionData) {
                 var option = new Option(optionData.Text, optionData.Value);

                 if ($.browser.msie) {
                     dropdownList.add(option);
                 }
                 else {
                     dropdownList.add(option, null);
                 }
             });
         }
     });
 }