You can customize the status bar's text to be a certain string when you move your mouse over an ad. To prevent phishing and other malicious attacks that mislead visitors, when the mouse hovers a link, Firefox will always show the full URL. This customization does not work in such cases.
Browser Setting
All browsers have different options to enable and disable certain JavaScript behaviors. In Mozilla Firefox:
- On the menu, follow Tools\Options\Content
- Next to "Enable JavaScript" (check if it's already enabled), click on Advanced
- From here, you can enable/disable certain JavaScript features:
- Move or resize existing windows
- Raise or lower windows
- Disable or replaced context menus
- Hide the status bar
- Change status bar text
Demo and HTML Code
Move mouse over this link to change status bar message
This is done with the following JavaScript code:
Troubleshooting 
