I have studied the problem from the given screen shot .
If all the 4 fields are eclosed by a single text area then you have to unlock the rightmost key by selecting it.
Then after it will spread across the screen.
If all the fields are indivisual then do this for all the fields.
Just do it i think you'll get your solution.
Thanks for the answer but that doesn't do what I want it to do.
By unticking those boxes it just keeps everything where it is it doesn't expand the fields to make use of the screen.
But it put me on the right track.
Actually I went for a different tact by instead of them automatically resizing which doesn't seem to work, I have them automatically centering so that when the screen expands or contracts it will expand and contract the surrounding textbox but will keep the fields centered.
I actually prefer this to be honest as it seems more uniform.
Thanks for your help though.