JavaScript通过select动态更换图片的方法

...<script language="JavaScript" type="text/javascript" >function setBeerIcon() { var beerIcon = document.getElementById("beerIcon"); beerIcon.src = "images/"+getSelectValue("beer")+".jpg";}</script>...<img border="0" src="" id="brandIcon" alt="brand" /><select name="beer" id="beer" onChange="setButton();setBeerIcon();"><option value="--Select--">Select beer</option>  <option value="heineken">heineken</option>  <option value="sol">sol</option>  <option value="amstellight">amstellight</option>  <option value="coronalight">coronalight</option>  <option value="coronaextra">coronaextra</option>  <option value=""></option></select>