how to go to next level of unit building?

[sam1on1]

hi guys,
just need some help, have researched armor6,war horses 5, centralization 4 but still am not able to develop heavy units. can anybody help me as how to do that.
thanks

[tiger]

you are probably playing v4a rules so this are requirements which you can see under game rules. all relams except R1-R4 and R10 are played by these rules.
Units requirements:
Light:
Spearmen: Melee attack 1;
Archers: Range attack 1;
Swordsmen: Melee attack 1;
Light cavalry: Melee attack 1; War horses 1;
Battering rams: Tactics 1;

Heavy:
Heavy Spearmen: Centralization 4; Tactics 5;
Heavy Archers: Centralization 4; Range attack 7;
Heavy Swordsmen: Centralization 4; Melee attack 7; Armor 7;
Heavy cavalry: Centralization 4; Melee attack 7; Armor 8; Tactics 1; War horses 5;
Catapults: Centralization 4; Range attack 7; Tactics 5;

Elite:
Phalanx: Tactics 7; Armor 12;
Elite archers: Range attack 14;
Guardians: Melee attack 13; Armor 13;
Paladins: Melee attack 14; Armor 14; Tactics 3; War horses 7;
Trebuchets: Tactics 7; Range attack 14;

[chegewara]

just point with mouse on "N/A" and you will se what you need to build it. sometimes you need just to relogin if you have all requirements and still you cant build it