proc mixed for specific group comparison

[superbibi]

Hi SAS Users,

I am new for proc mixed procedure. I have repeated data with 8 follow-up visit including baseline. I genearte a similar data set as below.

I want to use proc mixed to do the analysis and compare only each follow-up visit to baseline adjusitng with tukey method. 

Could you kindly help me to figure out what code should I insert or midify?

Thank you.

data forglm(keep=person gender y1-y4)
formixed(keep=person gender visit y);
input person gender$ y1-y4;
output forglm;
y=y1; visit=1; output formixed;
y=y2; visit=2; output formixed;
y=y3; visit=3; output formixed;
y=y4; visit=4; output formixed;
datalines;
1 F 21.0 20.0 21.5 23.0
2 F 21.0 21.5 24.0 25.5
3 F 20.5 24.0 24.5 26.0
4 F 23.5 24.5 25.0 26.5
5 F 21.5 23.0 22.5 23.5
6 F 20.0 21.0 21.0 22.5
7 F 21.5 22.5 23.0 25.0
8 F 23.0 23.0 23.5 24.0
9 F 20.0 21.0 22.0 21.5
10 F 16.5 19.0 19.0 19.5
11 F 24.5 25.0 28.0 28.0
12 M 26.0 25.0 29.0 31.0
13 M 21.5 22.5 23.0 26.5
14 M 23.0 22.5 24.0 27.5
15 M 25.5 27.5 26.5 27.0
16 M 20.0 23.5 22.5 26.0
17 M 24.5 25.5 27.0 28.5
18 M 22.0 22.0 24.5 26.5
19 M 24.0 21.5 24.5 25.5
20 M 23.0 20.5 31.0 26.0
21 M 27.5 28.0 31.0 31.5
22 M 23.0 23.0 23.5 25.0
23 M 21.5 23.5 24.0 28.0
24 M 17.0 24.5 26.0 29.5
25 M 22.5 25.5 25.5 26.0
26 M 23.0 24.5 26.0 30.0
27 M 22.0 21.5 23.5 25.0
;

data formixed2;
set formixed;
by person;
if first.person then base = y;
base +0;
diff = y - base;
output;
run;


proc mixed data=formixed2; 
class gender visit person; 
model y = base visit ; 
repeated / type=cs sub=person;
/*insert appropriate code for paired comparison with tukey adjustment*/
run;

[superbibi]

I used dunnett adjustement and upadted the code. It should produce what I want. I also use tukey to compare. 

proc mixed data=formixed2; 
class gender visit person; 
model y =  base visit ; 
repeated / type=cs sub=person;
lsmeans visit/diff adjust = DUNNETT;
lsmeans visit/diff adjust = tukey;
run;