Help! Please ask if the data returned by bitmex after the failed order is false or null or undefine?

This code is used to place an order. This is a list of all the different ways SetContractType is credited in the database: Exchanges[1]. Set Margin Level ((80); exchanges[1].SetDirection (buy); exchanges[1].Buy ((close+20,amout);

The resulting system returned an overload error: Futures_BitMEX Futures_OP 0: 503: {error:{message:The system is currently overloaded. Please try again later.,name:HTTPError}}

I want to try again with the following infinite loop structure, but I don't know what the return value of the above error is? var id=null; while ((id==nullなたなたid==false) { This is a list of all the different ways SetContractType is credited in the database. Exchanges[1]. Set Margin Level ((80); Exchanges[1]. SetDirection (buy); id=exchanges[1].Buy ((close+20,amout); Sleep ((100)); I'm not sure.

What should be used in the while condition: null, false, undefined? or some other value?