[amibroker] AFL syntax for nested IIF ?

[amsiev]

What's the syntax in AFL for a double IF with following structure ?

IF True
       Do This ;
       Do That ;
       Do anything;
Endif

I'm working with arrays so I must use the double IF but my problem is 
that I just cannot get the correct syntax. There are in fact two 
problemens. First I only want the IIF to do something when the 
condition is true. Therefore I don't want the third part in case the 
IIF is false or the 'Do if false'. Second I want the IIF to do 
several things. Not just one. Following syntax is wrong. So what's 
the correct one ?

IIf(BarNumAct<=21, 
{
        Highs[BarNumAct] = Close;
        Lows[BarNumAct]  = Close;
        Range[BarNumAct] = (High - Low)/2;
}
,"");