added different installation procedure

INSTALL.txt

@@ -1,10 +1,12 @@
-to install liggghts post processing copy the following lines of code 
+to install *liggghts post processing* (lpp) execute the following 
+./install.sh
+
+
+
+
+to install *pizza.py* copy the following lines of code 
 into your bashrc (please change the variable CFDEM_lppPath according 
 to your system):
 
-============================================
-CFDEM_lppPath=/Users/s/work/parallelpizza/nightly_build
-
-alias lpp="python $CFDEM_lppPath/src/lpp.py"
-alias pizza  ="python $CFDEM_lppPath/src/pizza.py"
-============================================
+CFDEM_pizzaPath=/Users/s/work/parallelpizza/nightly_build
+alias pizza  ="python -i $CFDEM_pizzaPath/src/pizza.py"

install.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+if test "`id -u`" -ne 0
+	then 
+	echo "You need to run this script as root" 
+	exit 
+fi
+
+echo "checking for old installations..."
+if [[ -L /usr/bin/lpp ]]; then
+	echo "you need to uninstall old lpp versions first."
+	echo "you can do by so executing"
+	echo "sudo rm /usr/bin/lpp /usr/bin/pizza"
+	exit 1
+fi
+
+echo "setting symbolic links..."
+ln -s $(pwd)/src/lpp.py /usr/bin/lpp
+
+echo "checking installation..."
+echo "which lpp"
+echo $(which lpp)