Executing Collective Availability Checks

Hi,

I found following info from (http://help.sap.com/saphelp_470/helpdata/en/f6/868b5313b311d3b74f0000e8359ebc/content.htm)

• Choose Information systems ® Project System ® Structures ® Individual overviews ® Networks. Enter the PS info profile, as necessary. The initial screen for the information system appears.
• Enter the selection criteria and choose . You enter the required networks directly or select them via the project definition or WBS elements.

The individual overview for networks appears.

• In the information system only a few general functions are displayed as icons. By choosing you can display the functions you require. If the availability check is not displayed as , choose .

Problem is that i am not able to get the button ? any pointers on this will be helpfull.

Regards,

Jatinder