What is BuyStop,SellStop,BuyLimit,SellLimit??

[okwh]

Yesterday,
I start a EA with Demo Account,
In EA, OrderSend with BuyStop and SellStop for pending orders, two OK,
When one of this two pending Orders arrived Open, Ea will delete another.
But No any order display at trade windows after one pending order arrived Open.

I checked Account history windows ,and find record in below,
that Opened Order is delete, but that delete order by my EA shown in concelled.
What's wrong with them??

Bellow is recoed just befor 1 hous now:

........................................................
4664142 2006.11.29 08:30 buy stop 5.00 eurusd 1.3211 0.0000 0.0000 2006.11.29 09:44 1.3184 cancelled ***********
4664150 2006.11.29 08:30 sell stop 5.00 eurusd 1.3182 0.0000 0.0000 2006.11.29 09:44 1.3182 deleted [no money]
4666993 2006.11.29 09:45 buy stop 5.00 eurusd 1.3204 0.0000 0.0000 2006.11.29 09:48 1.3178 cancelled *******
4667028 2006.11.29 09:45 sell stop 5.00 eurusd 1.3176 0.0000 0.0000 2006.11.29 09:48 1.3176 deleted [no money]
4667412 2006.11.29 09:50 buy stop 5.00 eurusd 1.3204 0.0000 0.0000 2006.11.29 10:06 1.3173 cancelled ***********
4667421 2006.11.29 09:50 sell stop 5.00 eurusd 1.3170 0.0000 0.0000 2006.11.29 10:06 1.3170 deleted [no money]
.......................................

[okwh]

Inside test, all OK, no problem.

but atteached to demo account for real work demo, these errors take place.

.......
OrderSend(Symbol(),OP_BUYSTOP,LotsOptimized(),PriceB,3,0,0,"",MAGICMA,0,Blue);
OrderSend(Symbol(),OP_SELLSTOP,LotsOptimized(),PriceS,3,0,0,"",MAGICMA, 0,Red);

[okwh]

5.00 is too large!!! I find it

[[Deleted]]

I am new to MQL4. I am confused with buylimit, buystop,selllimit and sellstop. I do know what is wrong with the following code:
ticket = OrderSend(Symbol(), OP_SELLLIMIT, Lot_size, SL, 0,SL+stoploss*Point,SL - takeprofit*Point, "dragon player", magic, exp, Green);
I keep getting error code 3 --- invalid trade parameters.
Anyone can help me with this?

[Slava]

Please refer to client terminal user guide.

Sell Limit open price should be higher than current price.