[amibroker] Ploting price related line

[jflynnnz]

I want to chart lines at particular price levels.  I have 
constructed a line of code however this also plots when price is 
outside that specified in the code.

I would appreciate if someone could modify my code. 

IIf (((Close > 20) AND (Close < 28)), Plot  
25,"",colorDarkGrey,styleNoTitle),Null); 

Thanks