<appsettings>
<add key="production" value="http://www.production.com">
<add key="ProductionconnectionString" value="server=localhost;...." >
<add key="testconnectionString" value="server=localhost;...." >
</appsettings>
Public Application_BeginRequest()
{
bool production=false;
if(Request.URL.Host==ConfiqurationManager.Appsettings("production"))
{
Production=true;
}
}

if(Production==true)
{
context.items.add("connectionStrings",ConfiqurationManager.Appsettings("production"))
}
else
{
context.items.add("connectionStrings",ConfiqurationManager.Appsettings("test"))
}
}