Pushing submit buttons twice
This is a very easy but effective way to stop impatient users push submit buttons more than once.
Once pushed, the buttons becomes disabled (not pushable anymore) and changes its text to "Please wait ..."
(or whatever you want).
<form name="myExampleForm" action="foo.php">
Proper way of using popups
First of all, don't use popups. There are only a few rare cases i can think of that
justify to use popups.
it should open the popup url in a new browser window.
And if the popup is already open, but maybe hidden behind other windows, let it
bring on top.
returns false so that the href is not followed. Otherwise, the href is followed and
a new browser window is opened.
Removing the scrollbars is ok, but please keep the window resizable. There are always
reasons for your content to need more room than you thought.