Using Ajax To fade page color to white and back

morteza · December 6th, 2010, 05:41 AM

Hi,Dear Imar
When we click sign out link in p2p forum a message window appear and page colors begin fading to black and white .
How it happen?

Imar · December 6th, 2010, 05:49 AM

Hi there,

To find out stuff like this yourself, try this:

1. Open the source for the page and search for Log Out. You'll see something like this:

Code:

<a rel="nofollow" href="http://p2p.wrox.com/login.php?do=log...5073fd53f70f05" onclick="return log_out('Are you sure you want to log out?')">Log Out</a>

2. Next, search in the linked JavaScript files for the function called log_out. In this case, you find it in: vbulletin_global.js. The function looks liike this:

Code:

function log_out(confirmation_message)
{
 var ht = document.getElementsByTagName("html")[0];
 ht.style.filter = "progid:DXImageTransform.Microsoft.BasicImage(grayscale=1)";
 if (confirm(confirmation_message))
 {
  return true;
 }
 else
 {
  ht.style.filter = "";
  return false;
 }
}

So, it appears it's done with an IE (only) Filter. Just in case you're going to ask how filters work: http://msdn.microsoft.com/en-us/libr...47(VS.85).aspx

Cheers,

Imar