limit how many items can sell on online store

[2BarL]

I have on online store and have items that I just have one of. How can I make the item unavailable once an order is placed for it?  Right now, it is allowing people to order it over and over and it was a mess yesterday. I had to go immediately and delete it from my website before anyone could order it again. I tried putting an inventory of just 1 in it but it still did not stop someone from ordering it once that one had been sold.