鼠标触发事件~~!! 求助~

<html>
<head>
<style type="text/css">
span{  cursor:pointer; font-size:12px; }
#div0,#div1{display:none; font-size:12px; }
</style>
<script language = "javascript">
function dltChg(idx)
{
var div = document.getElementById("div" + idx);
div.style.display = "block";
div = document.getElementById("div" + (idx?"0":"1"));
div.style.display = "none";
}
</script>
</head>
<body>
<div>
<span onmouseover="dltChg(0)">我要组装电脑</span>
<span onmouseover="dltChg(1)">我要卖电脑</span>
</div>
<div id="div0">
<input type="text" name=""><select name=""></select><input type="radio" name=""><input type="radio" name="">
</div>
<div id="div1">
<textarea name="" rows="4" cols="30"></textarea><input type="submit">
</div>
</body>
</html>