idl loops urgent! : Idl-pvwave

Hi
I have an array which is [15,13,2191] filled with 1's and 0's. I need to find when there are four or more consecutive events in this array ie when there are four or more consecutive 1's in the array. I have made a set of loop

for j=0,14 do begin
for z=0,12 do begin
for i=0,2190 do begin
if array(j,z,i) eq 1 then begin
number_in_row=number_in_row+1
endif else begin
number_in_row=0
endelse
if number_in_row ge 4 then begin
event=event+1
endif
endfor
endfor
endfor

index=intarr(2191) index(*)=0
number=0
for j=0,14 do begin
for z=0,12 do begin
for i=0,2190 do begin
if array(j,z,i) eq 1 then begin
if array(j,z,i-1) eq 0 then begin
index(i)=number
number=number+1
endif else begin
index(i)=index(i-1)
endelse
endif
endfor
endfor
endfor

WHen I run this it gives my a sensible number of events approx 110. However when I do help,number I get over 5000 values and the groups of 1's are not given a single number nor are they number consecutively?!?!?!?
When I do print,histogram(index) I get an array of 0,1,2..s but if I do print,WHERE(histogram(index) ge 4) I just get zero.

Could someone please tell me if there ifs an easier way to do this or if there is a way of fixing this code.

thanks
endfor
endfor