@Condor,thank you for reply!

My code in FF3 has all the effect what I need.

1)My form.xf.CheckerInfoDisplayForm is a custome component that show plain html table, in IE7 the form is not display sometimes or leave the display area blank!

2)But why in FF3 it is ok?

3)A layout:'slide' with easing:'none' still has the slide effect!