Autopostback and Smartnavigation works fine, but not for me

[catweezle2010]

Hello NG,
I need autopostback to verify the user's input. They have to fill in
the number of pices to order and I have to check each time if the
allowed number is reached and something more.

This function works fine. The Problem is, that the autopostback will
take affect, when the user left the control for an other. Here he
starts the new input. Meanwhile the postback takes effect and publish
the new calculated site. The smartnavigation take the position to the
control which caused the postback.

How can I keep the focus on the new control?

Switch off the smartnavigation wouldn't help, I think.

Thanks for helping.