[ns] Having problem installing ns 2.1b7...gives this error message

I want to use ns 2.1b7 cos the version I got has an ATM patch already which I need for my thesis.I try to configure it and I get the error message below. __ _ [EMAIL PROTECTED] Desktop]# cd ns-2

[ns] Having problem installing ns 2.1b7...gives this error message

I want to use ns 2.1b7 cos the version I got has an ATM patch already which I need for my thesis.I try to configure it and I get the error message below. ___ [EMAIL PROTECTED] Desktop]# cd ns-2-