i have this html, this is generated dynamically based on question number

 <fieldset id="selectfield">
            <label class="select">What ur is Profession?
            </label>
            <br>
            <div class="ui-select"><a href="#" role="button" id="72+_select-button" aria-haspopup="true" aria-owns="72+_select-menu" data-theme="c" class="ui-btn ui-btn-icon-right ui-btn-corner-all ui-shadow ui-btn-hover-c ui-btn-up-c"><span class="ui-btn-inner ui-btn-corner-all" aria-hidden="true"><span class="ui-btn-text">Business</span><span class="ui-icon ui-icon-arrow-d ui-icon-shadow"></span></span></a>

            <select name="selectedObjects" id="72+_select" data-native-menu="false" tabindex="-1">
                <option value="-1">--Select--</option>
                    <option value="769">Salaried</option>
                    <option selected="selected" value="770">Business</option>
                    <option value="771">Self Emp</option>
            </select></div>
        </fieldset>

click button is

     <div data-theme="c" class="ui-btn ui-btn-corner-all ui-shadow ui-btn-hover-c ui-btn-up-c" aria-disabled="false"><span class="ui-btn-inner ui-btn-corner-all" aria-hidden="true"><span class="ui-btn-text">Next</span></span>
        <input type="submit" id="72+_b" onclick="return SaveDropDown(this);" value="Next" class="ui-btn-hidden" aria-disabled="false">
     </div>

i have written this JS in SaveDropDown(this)

       function SaveDropDown(button) { 
        var fieldsetName = getQuestionName(button.id)+'+_select'; 
        var select = $(fieldsetName +"option:selected").val(); 
        return false;
    }

the questionname function is

     function getQuestionName(buttonid) { 
        var splitstr = buttonid.split('+');
        var fieldsetName = '#' + splitstr[0];
        return fieldsetName;
    }

but its returning the undefined how do i retrieve the select value dynamically.

any help is appreciated.