Create unique id based on two variables

[di_niu0]

Hello All, 

As shown above, I'm trying to assign unique id based on var1 and var2. Not sure how to do it. 

var1     var2        id

1           1            1

1           1            1 

1           3            2

2           1            3

2           1            3

2           2            4

Thank you! 

[PeterClemmensen · Accepted solution]

Try this

data have;
input var1 var2;
datalines;
1 1 
1 1 
1 3 
2 1 
2 1 
2 2 
;

data want;
   set have;
   by var1 var2;
   if first.var2 then id + 1;
run;

[di_niu0]

Thank you very much!!!!!!!!

[PeterClemmensen]

Anytime, glad to help.