# OpenLink Virtuoso Universal Server: Documentation - on-post

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## on-post

Container for code that should be executed when the element gets a post.
< on-post >(EventHandler)</ on-post >
Description

The code contained in this element is executed when the element gets a post. For fields and forms, this is a context for an a SQL compound statement that will be executed. The statement should end with a return 1 or 0. The implicit return is 0. A return of 1 means that the post is fully handled here and not to be passed on to the parent chain. A 0 means that the post was not handled and the next control up the chain will try.

The context has a self which is the page, a vspx_control which is the control which defines this handler, and a origin_control, which is the control that first got the post event. This will be a data field or button. The vspx_event with the post's data will be in the variable event.

The interpretation of the return value is the same for other event handlers. SQL conditions signalled will go to the page, these condition handlers are invoked in no special context, hence the declare handler for SQL construct should not be used to pass control between handlers, but only within handlers.