Issue with setting height of dialog object

I have a dialog box that I change the title off and content of as a user fills out a form eventually getting to the end of the process and the dialog box closing.

works perfectly in Firefox and when testing in IE8 I noticed that the height of the dialogs were not getting set. As each step required more or less space I was resizing the dialog using the following line of code

$('div#dialogueBox').dialog("option", "height",400);

now moving between firefox and ie I noticed that it wasn't working properly setting the height to be 0 in effect.

my solution was to use the following

$('div#dialogueBox').dialog("option", "height",($.browser.msie?"400px":400));

turns out that IE8 required the addition of the "px" definition and firefox didn't like it when I added the "px" to the height value.

would be neater if this was handled by the dialog functionality rather than by the user. I should be able to use either

$('div#dialogueBox').dialog("option", "height","400px");

or

$('div#dialogueBox').dialog("option", "height",400);

to set the height of my dialog.

Thanks