If you are looking for a sample flex code for network diagram or flex drawing related code then this post may be useful for you. Exactly say if you are looking for flex code which should connect two nodes (images) using line component. Like User can draw or connect line from one node to another node in network diagram.
Try this link you can find similar application which covers above requirement. You can connect two nodes using arrow in this application.
Object Handles Library
If you want to move or resize flex object like flex components like combo box, button, rectangle and even line then try this action script library Object Handles.
Flex Diagram Application
Flex Diagrammer library
You can also try Flex Diagrammer library and you can build your own Diagrammer and easily extend nodes and links.
Also try our old post about Useful Flex Libraries.