looping ~error

[alex]

Hello.
I can not loop this part:

do regend = 1996:4,2001:1
@dfunit gdpq regstart regend
end do

how can Ideal with that. pleae help with that.

Thanks.

-------- coding---------
cal 1947 1 4
all 2001:1

open data usadata.rat
data(format=rats) / m2 gpdi gdpdefl unemprate gdpq

compute regstart =1947:5

do regend = 1996:4,2001:1
@dfunit gdpq regstart regend
end do

error message : SR10. Missing Values And/Or SMPL Options Leave No Usable Data Points
The Error Occurred At Location 0904 of DFUNIT
Line 35 of DFUNIT

[moderator]

Add an explicit

source dfunit.src

before the loop.

[alex]

Thank you very much..