How to get Index of sub item of an array

Question

var s_a = new Array();

s_a[0]="";

s_a[1]="Badakhshan|Badghis|Baghlan|Balkh|Bamian|Farah|Faryab|Ghazni|Ghowr|

Helmand|Herat|Jowzjan|Kabol|Kandahar|Kapisa|Konar|Kondoz|Laghman|Lowgar|

Nangarhar|Nimruz|Oruzgan|Paktia|Paktika|Parvan|Samangan|Sar-e Pol|Takhar|

Vardak|Zabol";

s_a[2]="Berat|Bulqize|Delvine|Devoll (Bilisht)|Diber (Peshkopi)|Durres|

Elbasan|Fier|Gjirokaster|Gramsh|Has (Krume)|Kavaje|Kolonje (Erseke)|Korce|

Kruje|Kucove|Kukes|Kurbin|Lezhe|Librazhd|Lushnje|Malesi e Madhe (Koplik)|

Mallakaster (Ballsh)|Mat (Burrel)|Mirdite (Rreshen)|Peqin|Permet|Pogradec|

Puke|Sarande|Shkoder|Skrapar (Corovode)|Tepelene|Tirane (Tirana)|Tirane

(Tirana)|Tropoje (Bajram Curri)|Vlore";

s_a[3]="Adrar|Ain Defla|Ain Temouchent|Alger|Annaba|Batna|Bechar|Bejaia|

Biskra|Blida|Bordj Bou Arreridj|Bouira|Boumerdes|Chlef|Constantine|Djelfa|El Bayadh|

El Oued|El Tarf|Ghardaia|Guelma|Illizi|Jijel|Khenchela|Laghouat|M'Sila|

Mascara|Medea|Mila|Mostaganem|Naama|Oran|Ouargla|Oum el Bouaghi|Relizane|

Saida|Setif|Sidi Bel Abbes|Skikda|Souk Ahras|Tamanghasset|Tebessa|Tiaret|

Tindouf|Tipaza|Tissemsilt|Tizi Ouzou|Tlemcen";

s_a[4]="Eastern|Manu'a|Rose Island|Swains Island|Western";

s_a[5]="Andorra la Vella|Bengo|Benguela|Bie|Cabinda|Canillo|Cuando Cubango|

Cuanza Norte|Cuanza Sul|Cunene|Encamp|Escaldes-Engordany|Huambo|Huila|La

Massana|Luanda|Lunda Norte|Lunda Sul|Malanje|Moxico|Namibe|Ordino|Sant Julia

de Loria|Uige|Zaire";

s_a[6]="Anguilla";

s_a[7]="Antartica";

.

.

.

s_a[105]="Andhra Pradesh|Arunachal Pradesh|Assam|Bihar|Goa|Gujarat|Haryana|

Himachal Pradesh|Jammu and Kashmir|Karnataka|Kerala|Madhya Pradesh|

Maharashtra|Manipur|Meghalaya|Mizoram|Nagaland|Orissa|Punjab|Rajasthan|

Sikkim|Tamil Nadu|Tripura|Uttar Pradesh|West Bengal|Chhattisgarh|Uttarakhand|

Jharkhand|Telangana ";

 

The above code is my array.I need to get the index of an item in the last row(s_a[105])

Example:

i have the value 105 in a variable.Then i need index of Assam as 2 .Please help me.It should be in Javascript.Please...