Problem with loops in Maple 11

Hi,

I encountered some difficulties while trying to plot a function depending on a discrete parameter that I included in a for loop.

This is the code :

f(,,,,):=...; (rather complicated function 11 parameters)

with(plots):

tracer:=proc()

local p,k,L,ind:

L:=NULL:

ind:=...; (it is a 3x8 matrix)

for k from 1 to 8 do

for p from 1 to 8 do

L:=L,plot3d(f(x,y,ind[2,k],ind[3,k],ind[2,p],ind[2,p]),x=0..1,y=0..1,numpoints=1000):

end do:

end do:

display(L);

end proc;

tracer();

Maple prints that it can't evaluate the function, which is perfectly plotable if I plot it for specific values of k and p... I think it can't reach for the value of ind[2,k], etc. inside the loop, which is kind of annoying ...

Any idea about how to solve this problem ?

[IMG]file:///C:/Users/Charles/AppData/Local/Temp/moz-screenshot-7.jpg[/IMG][IMG]file:///C:/Users/Charles/AppData/Local/Temp/moz-screenshot-8.jpg[/IMG]