convert custom indicator to EA (expert advisor) -- 2

Project Description: I have a custom indicator that gives sell and buy alerts. I want to convert it to EA that convert these alerts into orders as follows " 1. when a buy signals comes, it closes the sell order and opens a buy order. 2. when a sell signal comes , it closes the buy order and open a sell order. depending on these two rules above : a. the maximum opened orders at the same time is always only one trade per signal. b. there is always a trade opened. c. I have to be able to set a default lot size to the orders. d. set a stoploss and target profit in pips. e. time frame is already be set in my indicator. when the ea is launched it must check if there is order opened or not, to make sure not to open more the one order at the same direction. what I need is to convert the code itself from an indicator code to EA code ( the use of icustom function is not allowed ) ## you can contact me if any further information is needed .