how to use bit string in fitness ga(tool) genetic algorithm matlab

i have problem in my program routing(ga tool) when i find the result i want the ga tool to stop but it still running until the generation equal 0 ; i use the bit string type so i want way to put condition in my project to stop the running when find the first solution for example (ans = 100)

--------- my code---------

function g =myfitness2(X)
LAMDA=X(1)+X(2)*2+X(3)*4+X(4)*8+X(5)*16
TYPE=1;
ITER=1000;
R1=Routing3a(TYPE,LAMDA,ITER);
g=-R1
end
........

result of program it

LAMDA 3
g=33.25
LAMDA 17
g=-100
LAMDA 11
g=-100