用js实现登陆后隐藏button
大家帮我看一下有什么问题 现在点button就是说页面有错误 具体也不说什么错误
<script type="text/javascript">
function fdenglu()
{
if (Session("user_name")=Null)
var denglu1=document.getElementById("Button1").style .visibility ='visible';
else
var denglu2=document.getElementById ("Button1").style .visibility ='hidden';
}
function fzhuce()
{
if (Session("user_name")=Null)
var zhuce1=document.getElementById ("Button2").style .visibility ='visible';
else
var zhuce2=document.getElementById ("Button2").style .visibility ='hidden';
}
function fzhuxiao()
{
if (Session("user_name")=Null)
var zhuxiao1=document.getElementById ("Button9").style .visibility ='hidden';
var zhuxiao2=document.getElementById ("Button9").style .visibility ='visible';
}
</script>
<input type="button" id ="Button1" value= "登陆" onclick ="fdenglu()"&"Button1_Click" />
<input type="button" id ="Button2" value= "注册" onclick ="fzhuce()"&"Button2_Click" />
<input type="button" id ="Button9" value= "注销" onclick ="fzhuxiao()"&"Button9_Click"/>