Multiple data for same record ID

[tranguyen0205]

Hi, 

How can I fill in the cohort number for the same record ID but at different time points?  Please see 

What the dataset looks like:

Record ID	Timepoint	Cohort #
1	scr	1
1	bl	.
1	w8	.
1	m6	.
1	m12	.
2	scr	1
2	bl	.
2	w8	.
3	scr	2
3	bl	.
3	w8	.

What I want:

Record ID	Timepoint	Cohort #
1	scr	1
1	bl	1
1	w8	1
1	m6	1
1	m12	1
2	scr	1
2	bl	1
2	w8	1
3	scr	2
3	bl	2
3	w8	2

Thank you!

[A_Kh · Accepted solution]

data want;
	set have;
	by recordid;
	retain temp;
	if first.recordid then temp=cohort;
	if cohort eq . then cohort=temp;
	drop temp;
proc print;run; 

[tranguyen0205]

Thanks a lot! It works.