[ns] installation problem

[fd ss]

Hi there,
i am new to ns and i tried to install ns for the first time under cygwin but i could not. i received the following messages :
./install:line 20:$' \r ' :command not found
./install:line 21:syntax error near unexpected token ' $' {\r ' '
;/install:line 21: ' die<> {
i believe that i followed every step correctly  and  i re-install cygwin and ns many times with the same result. i used ns-allinone-2.33
please help me
thank you