question about buy stop

I tried to place this order, but it says Invalid SL or TP.

I am wondering what I did wrong. Please advice.

Thanks

You're trying to place a pending buy order at the exact same level as the Ask price available in the market.

Buy at market ("Instant Execution" in MT4 I think) if you're happy with the market price.

I dun get it.

I want to set up a buy Order if thE price get to 1.57810, the current price is 1.57815, that is 4 pips away, can' do that?

that's NOT 4 pips. that's 5 PIPETTES. big difference.

you can't place orders wherever you like. each broker has their own set of rules as to how close to the current price you can set orders and stoplosses and takeprofits etc. just play around with the demo account and you will figure it out.

also learn the difference between market / limit / stop orders are, as you clearly have no idea which is half the battle.