<select id="udf_list" class="udf_list" onchange="SelectUDF()">
 <option value="1" 
             label="a"
             title="aa">2 </option>
 <option value="3" 
             label="b"
             title="bb">4 </option>
 <option value="5" 
             label="c"
             title="cc">6 </option>
 </select>

 <select id="udf_list" class="udf_list" onchange="SelectUDF()">
     <option value="1" 
           label="a"
           title="aa">2 </option>
 
     <option value="3" 
           label="b"
           title="bb">4 </option>
 
     <option value="5" 
           label="c"
           title="cc">6 </option>
 </select>