By default, the completion box is automatically displayed
whenever you pause for more than 500 milliseconds after typing a period.
You can disable the automatic display of the code completion box
so that it is displayed only when you type Ctrl-spacebar.
To disable the automatic display of the completion box:
Choose Tools Options.
Expand the Editor Settings node and select the Java or HTML Editor.
The Java or HTML Editor properties are displayed in the right pane of the
Options window.
Select the Auto Popup Completion Window property and set it to
False.