Database backup and restore

Question

Hi,

I have a retail software that uses the sql server 2005 database in the stores. I have 5 stores where this software and sql server 2005 is installed. I ma taking the backup of the database everyday before start the sale.

Now this database size is increasing everyday. This creates a problem to send this backup to the server through mail or ftp.

Is there any mechanism into the sql server to take only that part of data which is new or updated i.e. only the transaction of previous day or any updated thing.

Please help me.