ASP.NET ConnectionString not working

In my .aspx page VS2008 C# ASP.NET I have this line:
-----------
<asp:SqlDataSource ID="mySqlDataSourceID" runat="server"
                                ConnectionString="<%$ ConnectionStrings:myConnectionString1 %>"
                                onselecting="mysomething"                                
ProviderName="<%$ ConnectionStrings:myConnectionString1.ProviderName %>"
        SelectCommand="SELECT * from MyTab">
</asp:SqlDataSource>
-----------
The web.config has:
<configuration>
  <connectionStrings>
    <add name="myConnectionString1" connectionString="DATA SOURCE=mySOMETHING1;PASSWORD=myPwd;PERSIST SECURITY INFO=True;USER ID=myID"
     providerName="Oracle.DataAccess.Client" />
  </connectionStrings>
</configuration>
------
Above works.

But I need to get rid of "myConnectionString1" under   <connectionStrings> in the web.config file.
Instead I need to use the similar stuf under: <appSettings> in the web.config file.

The current contenct in web.config ther is:
  <appSettings>
<add key="myKey1" value="Data Source=mySOMETHING1;Persist Security Info=True;User ID=myID;Password=myPwd;"/>
</appSettings>

The value of "myKey1" in the   <appSettings> is same as the myConnectionString1under  <myConnectionString>.

How could I use "myKey1" of   <appSettings> above instead of "myConnectionString1" in   <connectionStrings> for the SqlDataSource ID "mySqlDataSourceID" ?
In my .aspx.page?

I tried:
<asp:SqlDataSource ID="mySqlDataSourceID" runat="server"
                                ConnectionString="<%$ AppSettings["myKey1"] %>"
                                onselecting="mysomething"                                
ProviderName="Oracle.DataAccess.Client"
        SelectCommand="SELECT * from MyTab">
</asp:SqlDataSource>

But It shows syntax error for the line:
                                ConnectionString="<%$ AppSettings["myKey1"] %>"

How to fix?