How to update table using webdynpro application using save button

Hi Experts,

  I created one webdynpro application in that application one button is there.my requirement is when he clicks that button it has to trigger workflow and in workflow if he approves then only it has to store the data into database and it has to send message otherwise it has to throw error message.Can anyone pls give me some idea on this.

Useful answers will be rewaded.

Thanks & Regards

Hareesh.