p:=11881379; s:=23; a:=45; A:= (s&^a) mod p; k:=123;

p := 11881379 

s := 23

a := 45

A := 250909

k := 123

ElGamalCryptoSystem("surenderrchiluka",[p,s,A]);

Error, (in cryptographytest:-ElGamalCryptoSystem) 

Key is the combination of 
P: A prime Number
s: A number in the range of 2 .. p-1
Alpha/a: Alpha published by the encrypted message reciver/ a Selected by the encrypted message reciver
k/T: another random number selected by you/ T recived with encrypted message

ElGamalCryptoSystem("surenderrchiluka",[p,s,A,k]);

["UJVRVAQMNDKAEIOEVAYQRMMA", 1777907]

ElGamalCryptoSystem("UJVRVAQMNDKAEIOEVAYQRMMA",[p,s,a,1777907],"decrypt");

"surenderrchilukazzzz"