Using same-name parameters from multiple same function fits in one plot?

Hi,

I fitted some data and stored the parameters in a file that I could load
with the "load" command. Now I wanted to plot many of these fits in one
graph but since I used the same function, the parameter names clash. So
far
I used something like

load "fit1.par"
a1=a
b1=b
load "fit2.par"
plot f(x,a,b),f(x,a1,b1)

Is there a more comfortable way? Especially I have 7 variables and 5
different fits, which make it a bit complicating looking.

Anton