Panel:SizeTo() More then Once?

I am making a Derma menu and I thought that it woud be nice to give it some sort of opening animation instead of just having a boring PopUp.
So I am using the Panel:SizeTo() function but it seems like I can only use it once on the same DFrame.
I tried writing it two times, since I want it to Size Up Horizontally first and then Vertically, in order to give it a nice effect but It reads the two function at the same time even if I put a different delay to both.
If you have never used this function but wish to help, here is an example.

Panel:SizeTo( # width, # height, # time, # startdelay, # ease )

[lua]frame:SizeTo( 610, 5, 0.5, 0, 1) – Example[/lua]
I even tried using a timer.Simple() but resulted in the same problem.
So to sum up quickly if you didn’t understand, I have a panel, I want to size it Horizontally first and then Vertically for a nice effect.
Thank you.