Summary

Communicating information from a script to a server is trivial: simply instantiate an object taking a URL source and put the information in the URL. Two-way communication is a bit trickier. The approaches range from externally linked <<script>>s that return content, to <<iframe>>s or even XMLHTTP objects. Regardless of the method chosen, some care must be taken to ensure that remote JavaScript-based Web applications are programmed in an extremely defensive manner and do not block waiting for content or fail due to unforeseen network issues.