new to MT4 and need help for a simple code

 
I am new to mt4 and not a programmer and need help to write a simple expert advisor

chart 4 hr; use line chart

buy : when 25ema crosses the price line that comes frome below , exit : when 6ema crosses the price line.

sell : when 25ema crosses the price line that comes frome above , exit : when 6ema crosses the price line.

TIA

Isaac