C# Webform ClientID prefix is a integer

I'm combining ASP.NET MVCand WebForm. When I do a Html.RenderPartial("xx") where xx contains a Webform the ClientID of this one is an integer. I doesn't seem to find the parent page through a RenderPartial! Anyone is aware of this behaviour? Could I possibly put a prefix? I'm using .NET 3.5 so I can set the ClientID to be static and I don't want to move to .NET 4. Is as the W开发者_运维百科ebForm rendered by RenderPartial didn't see this parent Page.

Any help would be appreciated!