What you are trying to do, the way you are trying to do simply won't work. On the OnClick you are defining a delegate by saying that the OnClick event will be handled by a method that you define. However, you can only give it a method name, you can't give it the whole parameters you want to pass as that is reserved by C#. The parameters will be an object (the sender) and Event Arguments related to the event.
So in a nutshell, yeah, you need the lnk1998Tot_Click method (which is a proper event handler for OnClick) and only in it you can call the SetGridContext().
Do note, LinkButtons have a CommandArgument that you can use when you want to pass a value to the event "Command" but here you can only pass a simple string I believe. (Check lnk1998.CommandArgument)
Tiago Microsoft Student Partner '09 - Portugal