I am trying to move my file to another system which is located in some other place, with this command:

rsync -avrz  src destination

It works fine. But what I need is to put this command in shell script and run it like:

#! /bin/sh
rsync -avrz  srcfilelocation destination

When it runs, it asks for the destination system password. I know that password and give it manually.

Now I have decided to assign the password to an environment variable, like pswd="destination system password". I need my shell script to read the password from this variable. How can I write a script to do this?