NS Validate problem

[qing@cs.su.oz.au (Yu Qing)]

Hi:
   After I download NS-2 , I follow the step(configure, Make, validate) .
   The first two step are all right, but When I run the validate, I meet the problem which I list below:
    *** ./test-all-simple
Tests: tahoe1 tahoe2 tahoe3 tahoe4 no_bug bug reno1 reno renoA reno2 reno3 reno4 reno4a reno5 telnet delayed phase phase1 phase2 timers stats
../../ns test-suite-simple.tcl tahoe1 QUIET
ld.so.1: ../../ns: fatal: libotcl.so: open failed: No such file or directory
Killed
Test output differs from reference output
Diagnose with: diff test-output-simple/tahoe1.test test-output-simple/tahoe1
Differences due to floating-point formatting are not significant.
../../ns test-suite-simple.tcl tahoe2 QUIET
ld.so.1: ../../ns: fatal: libotcl.so: open failed: No such file or directory
Killed
Test output differs from reference output
Diagnose with: diff test-output-simple/tahoe2.test test-output-simple/tahoe2
Differences due to floating-point formatting are not significant.
../../ns test-suite-simple.tcl tahoe3 QUIET
ld.so.1: ../../ns: fatal: libotcl.so: open failed: No such file or directory
Killed
Test output differs from reference output
Diagnose with: diff test-output-simple/tahoe3.test test-output-simple/tahoe3
Differences due to floating-point formatting are not significant.
../../ns test-suite-simple.tcl tahoe4 QUIET
ld.so.1: ../../ns: fatal: libotcl.so: open failed: No such file or directory
Killed
Test output differs from reference output
Diagnose with: diff test-output-simple/tahoe4.test test-output-simple/tahoe4
Differences due to floating-point formatting are not significant.
../../ns test-suite-simple.tcl no_bug QUIET
ld.so.1: ../../ns: fatal: libotcl.so: open failed: No such file or directory
Killed
Test output differs from reference output
Diagnose with: diff test-output-simple/no_bug.test test-output-simple/no_bug
Differences due to floating-point formatting are not significant.
   Thanks in advance.
   ~qing