<input name="radio1" type="radio" onclick="showDiv('radioDIV1')"/>

<input name="radio2" type="radio" onclick="showDiv('radioDIV2')"/>

<div id="radioDIV1" style="display:none;">
    radio1 content
</div>

<div id="radioDIV2" style="display:none;">
    radio2 content
</div>


<script type="text/javascript">
    function showDiv(objID){
        var divID = document.getElementById(objID);
                 //判断DIV显示状态 要是显示的就隐藏，隐藏的就显示
        if(divID.style.display=="block"){
              divID.style.display="none"
                }else{
              divID.style.display="block"   
        }
    }
</script>

------解决方案--------------------

[code=HTML][/code]<input type="radio" name="sex" id="man" onclick="show()">男
<input type="radio" name="sex" id="woman" onclick="show()">女
<div style="display:none" id="div1">
<p>第一个DIV！</p>
</div>
<div style="display:none" id="div2">
<p> 第二个DIV！</p>
</div>

<script>
function show(){
if(document.getElementById("man").checked){
	document.getElementById("div1").style.display="block";
	document.getElementById("div2").style.display="none";
	}else if(document.getElementById("woman").checked){	
	document.getElementById("div2").style.display="block";
	document.getElementById("div1").style.display="none";	
	};
	};
</script>