[REBOL] Arrays

[rebol . phb]

How do I access Arrays ??

Consider the following code fragment

; define a 3 X 3 array
myarray: array/initial [3 3] 0

for i 1 3 1
[
    marray/i/i: 1
]

doesnt work ....

for i 1 3 1
[
    marray/1/1: 1
]
 
does work

for i 1 3 1
[
    print marray/:i/:i
]

works, but 

for i 1 3 1
[
    marray/:i/:i: 1
]

doesnt

whats gong on ??