Problems installing IMP

[Devraj Mukherjee]

Hello All,

I recently downloaded a copy of Horde 1.2.4 and IMP 2.2 for installation on
my server devraj.org (RedHat Linux 6.x, Apache 1.3.x, PHP 3.x) I managed to
install Horde and IMP, using the PHP setup program and believe have got it
all right.

However when I try to access the IMP program using the web browser I get this
error:

Fatal error: Call to unsupported or undefined function page_open() in 
/home/devraj/devraj-www/horde/imp/index.php3 on
line 15

The installation is located at http://devraj.org/horde/imp/

Can anyone please help me out.

Regards,
Devraj