i have problem in parallel computing

please help me i use this code, but every time i get same answer while this code should get different answer.why? for example in every run i get answer 1.52 form labindex1 and 1.87 form labindex2. while when i run PSO2 or PSO3 in state nonparallel i get each time different answers. can anyone help me please? this is my code

matlabpool open
spmd(2)
    if(labindex==1)
        PSO2(  )
    else
        PSO3(  )
    end
end
matlabpool close