Solution of the SIR Model (with Birth and Death Rates) of the Spread of a Disease

Traceback (most recent call last): File "/var/www/cgi-bin/DiseaseSIRwBD.cgi", line 145, in runsolver(form) File "/var/www/cgi-bin/DiseaseSIRwBD.cgi", line 28, in runsolver b = form['b'].value File "/usr/lib/python2.7/cgi.py", line 541, in __getitem__ raise KeyError, key KeyError: 'b'