Appending two files vertically

Hi

Need ur help for the below question.
I have two files File-1 & File-2.

File-1(This is a fixed file i.e. the content of this file is not going to change over a period of time)
------
a
b
c
d
e

File-2 (This is a file which changes daily but the record count remains the same)
----------
10
20
30
40
50

I Require the output file as :
a,10
b,20
c,30
d,40
e,50

Thanks.

use paste command or pr command

paste -d"," file1 file2