Aquasim installation problem

I have installed ubuntu 32bit in Oracle VM Virtualbox on my current ubuntu
64 bit. Now I am trying to install Aquasim on it. I have also downloaded
the compilers which were mentioned in post #5
http://www.linuxquestions.org/questions/linux-software-2/install-aquasim-in-ns-2-34-a-4175466464/#5
but when I execute the following command:
$ export CC=gcc41 CXX=g++41 && ./install

it shows me following results/errors:


==============================
==============================
* Testing for Cygwin environment
============================================================
Cygwin not detected, proceeding with regular install.
============================================================
* Build XGraph-12.1
============================================================
configure: error: expected an absolute directory name for --prefix: ../
make: *** No targets specified and no makefile found.  Stop.
Can not create xgraph; But xgraph is an optional package, continuing...
============================================================
* Build CWeb
============================================================
Making cweb
gcc -g   -c -o ctangle.o ctangle.c
ctangle.w:75:12: warning: conflicting types for built-in function ‘strlen’
[enabled by default]
gcc -g -DCWEBINPUTS=\"/usr/local/lib/cweb\" -c common.c
common.w:1409:12: warning: conflicting types for built-in function ‘strlen’
[enabled by default]
common.w: In function ‘fatal’:
common.w:1176:1: warning: format not a string literal and no format
arguments [-Wformat-security]
gcc -g -o ctangle ctangle.o common.o
gcc -g   -c -o cweave.o cweave.c
cweave.w:79:12: warning: conflicting types for built-in function ‘strlen’
[enabled by default]
cweave.w: In function ‘print_cat’:
cweave.w:1739:1: warning: format not a string literal and no format
arguments [-Wformat-security]
gcc -g -o cweave cweave.o common.o
ln: failed to create symbolic link `cweave': File exists
ln: failed to create symbolic link `ctangle': File exists
============================================================
* Build Stanford GraphBase
============================================================
Making sgb
gcc41 -g -I/usr/local/sgb/include
-DDATA_DIRECTORY=\"/usr/local/sgb/data/\" -c gb_io.c
make: gcc41: Command not found
make: *** [gb_io.o] Error 127
Unable to create sgb library, but it's optional, so continuing...
============================================================
* Build GT-ITM
============================================================
sgb lib not found. gt-itm & sgb2ns could not be installed. Continuing..
============================================================
* Build zlib
============================================================
Building static library libz.a version 1.2.3 with gcc41.
Checking for unistd.h... No.
Checking whether to use vs[n]printf() or s[n]printf()... using s[n]printf()
Checking for snprintf() in stdio.h... No.
  WARNING: snprintf() not found, falling back to sprintf(). zlib
  can build but will be open to possible buffer-overflow security
  vulnerabilities.
Checking for return value of sprintf()... No.
  WARNING: apparently sprintf() does not return a value. zlib
  can build but will be open to possible string-format security
  vulnerabilities.
Checking for errno.h... No.
Checking for mmap support... No.
gcc41 -O -DNO_snprintf -DHAS_sprintf_void -DNO_ERRNO_H   -c -o example.o
example.c
make: gcc41: Command not found
make: *** [example.o] Error 127
Zlib make failed, but it's optional Continue ...
============================================================
* Build tcl8.4.13
============================================================
loading cache ./config.cache
checking whether to use symlinks for manpages... no
checking whether to compress the manpages... no
checking whether to add a package name suffix for the manpages... no
checking for gcc... gcc41
checking whether the C compiler (gcc41  ) works... no
configure: error: installation or configuration problem: C compiler cannot
create executables.
tcl8.3.2 configuration failed! Exiting ...
Tcl is not part of the ns project.  Please see www.Scriptics.com
<http://www.scriptics.com/>
to see if they have a fix for your platform.


Please help.