In many of the previous examples, links have been used to trigger events. When the user clicked or moved his mouse over a link, a link event was triggered. One link event, onClick , gets sent whenever someone clicks on a link. As we saw with mouse events, onMouseOver and onMouseOut also cause a link event to occur.
Table 12.5. Link events.
<a href="#" onClick='alert("This hotlink is out of service!"); return false;'>Click here</a>
or by using the void operator to guarantee that any return value from the function will be discarded:
In either case, the link was not supposed to take the user to another location, but instead to handle an event or call a function. (Make sure that any function calls in the URL have been defined.) Another note: if the "#" causes the browser to jump to the top of the page when the link is clicked, you can add a return false statement inside the onClick handler to keep the browser from checking the content of the href .
The following simple example uses the onClick event handler with a deactivated link and the return statement; the display is shown in Figure 12.13.
<html><head><title>Deactivate the hotlink</title></head> <body> <center> <a href="#" onClick='alert("This hotlink is out of service!"); return false;'>Click here</a> </center> </body> </html>
Figure 12.13. The user clicked on a deactivated link.