Hi, Kiran.
The first sentence in itself is confusing:
"If the import parameter LFIELDNAME does not have the initial value only those fields whos long name is the same as the contents of the paramenter"
If it has no initial value, how could anything have a long name the same as LFIELDNAME?
Isn't LFIELDNAME the matching parameter for the long name?
If this is the case, then there would be a match for any item with a blank long name.
You see my thinking in this?