libxstl problem

[knoppix <tar.bz@free.fr>]

Hi

I got that problem if anyone could help

I am trying to install a software on my debian

When I run the ./configure it says :

configure: error: Could not find libxslt anywhere, please check ftp:/
xmlsoft.org/ for libxslt >= 1.0.7.

so I downloaded it and when I make 
dpkg -i libxslt_1.1.2-2_i386.deb

it answers 
dpkg: error processing libxslt_1.1.2-2_i386.deb (--install):
 trying to overwrite `/usr/lib/libexslt.so.0.8.2', which is also in package
libxslt1.1
dpkg-deb: subprocess paste killed by signal (Broken pipe)
Errors were encountered while processing:
 libxslt_1.1.2-2_i386.deb

I was root when I did it

If someone could help I m really desesperate

Thank you 

Arkel