little problem with ea

 
hi, i have little problem with ea.

I want buy first transaktion for example 0.1 lot for long: if(Open[1]<ma && Close[1]>ma)
Now if profit in this transaktion will be for example +20 pips and (Open[1]<ma && Close[1]>ma) i want buy next 0.1 lot.

I have been trying this since 2 days and already i don`t have any idea