多按钮切换页面

<scripttype="text/javascript">
functionjava(){
varjava=document.getElementById("java");
vardt=document.getElementById("datastructure");
vardb=document.getElementById("database");

java.style.display="block";
dt.style.display="none";
db.style.display="none";
}

functiondt(){
varjava=document.getElementById("java");
vardt=document.getElementById("datastructure");
vardb=document.getElementById("database");

dt.style.display="block";
java.style.display="none";
db.style.display="none";
}

functiondb(){
varjava=document.getElementById("java");
vardt=document.getElementById("datastructure");
vardb=document.getElementById("database");

db.style.display="block";
java.style.display="none";
dt.style.display="none";
}
</script>
<p>&nbsp;</p>
<p>&nbsp;</p>
<div>
<form>
<inputtype="button"value="basic"onclick="java();"/><inputtype="button"value="servlet"onclick="dt();"/><inputtype="button"value="none"onclick="db();"/>
</form>
</div>
<divstyle="display:block;"id="java">
<p>1<ahref="http://www.javaworld.com/javaworld/javatips/jw-javatip75.html?page=1">Usenestedclassesforbetterorganization</a></p>
</div>
<divstyle="display:none;"id="datastructure"><ahref="http://www.zz172.com/tech/soft_pro/java-online/12066.html">1深入研究Servlet线程安全性问题(好文)</a><br/>
<p>&nbsp;</p>
</div>
<divstyle="display:none;"id="database">none</div>