how to modify a file using shell script

Shell Programming and Scripting
1

Hi,
i am using SuonOS and ksh.
i need to add data into a file(s.txt) using a shell script. i have to pass 3 parameters and these 3 paramaters should add into the file at end of the file.

File s.txt is look like,

---------------------------------
column1|column2|column3
data1|data2|data3
-----------------------------------
now i want a script and i will pass parameters as user1 user2 user3 to add data into new line, and
output file should be like

---------------------------------
column1|column2|column3
data1|data2|data3
user1|user2|user3
-----------------------------------

i know by using awk we can do this, but my trials got failed.
so pls provide some solution for this.

Thanks in advance

2 
echo "$1|$2|$3" >> s.txt