I've seen examples of how a child page can access stuff on a master page, but is there a way for the opposite?

I have a "save" button on my master page and my child page has textboxes for data entry. If the user click's on the save button, is there a way to kick off a sub/function that is in the child page (which would contain the error checking and sql statements for saving the data entry)?

I'm basically trying to avoid putting the same save button on every page.

Any insight is much appreciated!

Thanks!