Help with MQL4 WPR code

Hi, I've started learning some MQL4 but I'm running into problems and I can't seem to find a fix.

I'm just trying to use a simple indicator like Williams Percent Range (WPR) to enter and exit trades.

Before a trade is entered, I want it to close any open trades.

The WPR indicator is used to short when price crosses below -20 and long when it crosses above -80. I've put this in the OnTick() section.

Where do I put the close function so that it's not opening and closing trades on every tick?

Attached is my code so far. I don't know if the close function is even correct. Any help is appreciated.

Not bad for starting out... here are some improvements... see if you can tell me what was changed and why.

Thanks for the improvements.

Looks like you created a signal enumerator variable to indicate when the trade is long/short/flat.

The close code now uses the magic number to identify the specific trade to close. If I've missed anything, it's because I don't understand it lol!

I ran it though the strategy tested and realised I forgot to make only enter on H4 close data. What would be the best way to do this?

Subs. Thanks and
Regards