multiplot bode plot in one graph

[Li Nan]

I want to plot several bode plots in one graph. now I have the transfer function of each system, so i can darw the bode plot seperately. But i need to combine them and compare them. Can anyone give me some help?

[muks]

see this

[Li Nan]

that one won't help

the data tyte may be the problem, but i do not know how to solve it 

[Li Nan]

can anybody check out my vi and help me solve my problem?