单选按钮的显示与隐藏列项

$(function(){
 $("#fjgs").live("change",function(){//fjgs 单选按钮id
        var fjgs = $(this).val();
       if(fjgs == "Y"){
         document.getElementById("sanzheng1").style.display="none";
         
         document.getElementById("heyi").style.display="";
       }else{
         document.getElementById("sanzheng1").style.display="";
        
         document.getElementById("heyi").style.display="none";
         
       }
    });
});