Default Text Messaging Window while typing

[Addicted23]

Is there any way to change the size of the window when entering a new text message? I would love for it to be half the screen or even just 1/3 of the screen. It seems silly that the default only allocates like 1/8 of the screen to where you are typing. I don't need to see my last 3-4 text messages on the screen but I like to review what I typed in and that's hard to do with just a single line of space. Thanks.