ldap and blank space

[Andy]

when i search for an entry using the search filter

1) (cn=john doe)

i can get the same result with the following search filters

2) (cn=john      doe)
1) (cn=   john      doe   )

as you can see, there are additional blank spaces around the value.  i guess
ldap ignores the blank space.   how can i tell ldap to find the entry using
only #1 and NOT #2 and #3.  in other words, do not ignore blank spaces.
thanks