error while copying some text from a char array to another char array

if suppose my "strarr" char array holds the following text
(i.e.)
strarr()="text0 \text1/ text2 text3

i wanted the text which is enclosed within \ /
so the index of \ is x and the index of / is y
s = x+1
en = y-1
the text which i want is between the index value s & en now ..
to copy it to a separate char array "usern()" i do the foll but i get an error as \
"variable 'usern' is used before it is been declared"

dim j As Integer = 0
for i As Integer = s to en
usern(j)=strarr(i)
j+=1
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