Open orders with no indicators

[18081961]

Hi all,

i'm looking to open orders based in the difference of the present Bid to the Bid in the past. What I mean is;

if Bid now is x pips above than the Bid before then open an Buy order

if Bid now is x pips under the Bid before then open an Sell order.

But as this can put a no limit in the orders that are open how can we limit the open orders till the first open orders close?

Thanks in advance for any help

luis