Find the CSV file for updating data

Hi,

   I have created a SSIS Package, for this package the input is CSV file. The file will get updated once for two or three days. I have scheduled the Agent Job for this package to run it daily. What i wanted is, when the file is updated the package should run completely and update data in the Database, if the file is not updated then the package should identify that the file is the old and should not run the whole package. I think we can achieve this using SCRIPT task, if yes how we can??

Thanks,

Bhanu