求一javascript， button1点后另外一个button可用！解决方法

求一javascript， button1点后另外一个button可用！
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="申请" Width="72px" />
<asp:Button ID="Button3" runat="server" Text="确认" OnClick="Button3_Click" Width="80px" disabled="true" />
要求：页面打开的时候button3为disabled="true",点button1后，button3为可用disabled="false"

------解决方案--------------------------------------------------------

探讨

<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="申请" OnClientClick='show()' Width="72px" />

HTML code
function show()
{
if(document.all.Button3.disabled)
{
document.all.Button3.disabled = false;
}
}
]