>> s = 'How much wood would a woodchuck chuck?';
>> b1= strfind(s,'a')
b1 =
    21

>> b2=strfind('a',s)
b2 =
     []
>> b3=strfind(s,'wood')
b3 =
    10    23
>> b4=strfind(s,'Wood')
b4 =
     []
>> b5= strfind(s,' ')
b5 =
     4     9    14    20    22    32
>>
