According to Hadith, Laylatul Qadr is either on the 19th, 21st or 23rd night of Ramadhan. More emphasis is laid on the 21st and the 23rd, particularly the 23rd.

The A`maal for this night are:
 

1. The common A`maal for the three nights of Qadr, including:

a) Ghusl.

b) Namaz Two rak`aat namaz; in each rak`ah after Sura al¬Hamd recite Sura

al-Ikhlas 7 times.

c) Ziyarat of Imam Hussein

d)  Say 100 times:

'Astaghfirullaaha Rabbee Wa-atoobu Ilayh'

I seek forgiveness of Allah, and I turn (repentant) to Him.

e) Say 100 times:

'Allahumma il - `an Qatalata - ameeril mu'mineen'

O Allah, curse the ones who killed Ameerul Mu"mineen.

f) Du`a of Jawshane Kabeer is also recommended on this night.

2) Munajat of Imam Ali (a.s):

This is because Imam Ali was injured this night by the sword of Ibn-e-Mojlam (May Allah Curse be upon him). Our beloved Imam Ali(a.s) Suffered in pain for 2 night and was buried in Najaaf on 21st Ramadhan.

for more information, please follow the links:

http://alhassanain.org/english/?com=book&id=523

http://alhassanain.org/english/?com=book&id=715

http://alhassanain.org/english/?com=book&id=716

http://alhassanain.org/english/?com=book&id=717

http://alhassanain.org/english/?com=book&id=718