help against Pahlava - horse-archers vs. Cataphracts?

[Bootsiuv]

Press alt and place the cursor over an enemy...if it's an archer or skirmisher unit you're controlling, you should see the little cursor change from a bow/javelin to a sword. While holding down alt, click on the unit with your mouse button like you would to normally attack. Your archers/skirmishers will swith to their secondary weapons and charge into melee.