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 Surah alHamd recite Surah alIkhlas 7 times. c) Tasbih. Say 100 times: ‘Astaghfirullaaha Rabbee Waatoobu Ilayh’ I seek forgiveness of Allah, and I turn (repentant) to Him. d) Ziyarat of Imam Hussein e) Dua of Jawshane Kabeer is recommended on this night. f) Ziyarat of Ameenullah. 2. Munajat of Imam `Ali (a): 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. 3. Last ten night duas: From this night onwards, the Dua for the last ten nights is recited every night. Also, there is a special Dua for each of the last ten nights. Taken from:tebyan
source : sibtayn