I still isn't working.
Woops! i forgot that PERL has different operators for string and numerical comparison.

Also strip the newline character off of the string read from stdin. I haven't had an interest in PERL in a long time. There's a lot to remember (or forget depending on who you ask).

Code:
while ($pass ne 'abc123') 
{
     print "What is the password? \n";
     $pass=<STDIN>;
     chop ($pass);
}
print "Correct password.\n";