Thanks guys, the problem is that I have a 4 main layers one of which has a form in it. To get all these aligned cross borowser I created 4 external CSS files which load depending on OS and browser. I then created 4 blank layers which basically hide the bottom portion of the layer giving the impression that the layer is being minimised/maximised I am using a function to toggle the visibility of the 'blank' layers.
I can't hide the layer with the form in it cos then the min/max image would vannish. And I can't really split the layer up into more layers cos it is a knightymare to align layers with forms etc.
I'm going to ivestigate Toolmans suggestion and hope that it solves my problem *fingers crossed*