Request by scripts
For requests made by scripts, the story is different. The user may or may not do anything. The script is responsibel for invoking the request, and for handling the response. Again, this request can be of two types: synchronous and asynchronous. If a request is made in synchronous mode, the invoking function or script blocks (waits) till a response or error is received. Most browsers are unresponsive when there is a script running, till it completes. If the script takes long to complete, the browser might show a warning showing that the script in the page is unresponsive, and giving the user an option to abort the script.