Metatrader 4 Question

For example, just say I buy 1 Lot and then 5 mins later I sell .5 lot, instead of having 2 trades open (1 buy and 1 sell), how can I net the positions so it just says appears as 1 trade showing .5lot long?

I know its possible cause Ive done it b4 but ive since forgotten.

The reason I ask this is that not having the ability to net positions is really confusing when u scale in, and it makes it hard when u want to close the positon cause u have to open up every trade manually and close them all.

any help would be appreciated guys!