package phpldapadmin 1.2.2-4ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[sandeep kumar]

crash error on performing following command on ubuntu12.04 lTS
 sudo apt-get install phpldapadmin

ProblemType: Package
DistroRelease: Ubuntu 12.04
Package: phpldapadmin 1.2.2-4ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-29.46-generic 3.2.24
Uname: Linux 3.2.0-29-generic x86_64
ApportVersion: 2.0.1-0ubuntu12
Architecture: amd64
Date: Sat Aug 25 22:01:12 2012
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
PackageArchitecture: all
SourcePackage: phpldapadmin
Title: package phpldapadmin 1.2.2-4ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Spurge (spurgeonbj)]

Creating config file /etc/phpldapadmin/config.php with new version
 * Restarting web server apache2 (98)Address already in use: make_sock: could not bind to address 0.0.0.0:80
no listening sockets available, shutting down
Unable to open logs
Action 'start' failed.
The Apache error log may have more information.
                                                                                                                                                                                                        [fail]
invoke-rc.d: initscript apache2, action "restart" failed.
dpkg: error processing phpldapadmin (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 phpldapadmin
E: Sub-process /usr/bin/dpkg returned an error code (1)
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Script needs to take into account, existing instance of apache