how does selling work?, page-13

WW.- JW.
If you buy and sell on same day, having the same settlement day for both transactions, they will deposit / deduct the difference.
if you buy today and sell tomorrow they should deduct the full amount one day and deposit the full amount the next.That's what Westpac do with me.

Set up a spread sheet on office excel with a few formulas
and make entries as you buy sell and it will keep an accurate running total in you account and also a profit / loss total and an avr. cost. That way you always know what money you have, what the avr. is and what profits you make.
Hope it helps.

good luck