<select name=s1>
<option>aa</option>
<option>bb</option>
</select>
<input type=radio checked name=ra onclick="if(this.checked){document.all.s1.disabled=false;document.all.s2.disabled=true;}">
<select name=s2 disabled>
<option>aa</option>
<option>bb</option>
</select>
<input type=radio name=ra onclick="if(this.checked){document.all.s2.disabled=false;document.all.s1.disabled=true;}">
<option>aa</option>
<option>bb</option>
</select>
<input type=radio checked name=ra onclick="if(this.checked){document.all.s1.disabled=false;document.all.s2.disabled=true;}">
<select name=s2 disabled>
<option>aa</option>
<option>bb</option>
</select>
<input type=radio name=ra onclick="if(this.checked){document.all.s2.disabled=false;document.all.s1.disabled=true;}">
HideAllMenu(){
//hide 所有菜单}ShowLayer(str){
// 显示某一个菜单
}
</script>
<input name=aa value=1 type=radio onclick="HideAllMenu();ShowLayer('menu1');">show menu1 <br>
<input name=aa value=2 type=radio onclick="HideAllMenu();ShowLayer('menu2');">show menu2