>>   s = 'How much wood would a woodchuck chuck?';
>> a1= findstr(s,'a')
a1 =
    21
>> a2= findstr(s,'a') 
a2 =
    21
>> a3=findstr(s,'a') 
a3 =
    21
>> a4=findstr(s,'wood')
a4 =
    10    23
>> a5= findstr(s,'Wood')
a5 =
     []
>> a6=findstr(s,' ')
a6 =
     4     9    14    20    22    32
>> 
