Extract a text string – Access 97

Extract a text string – Access 97

In Access 97, I have a name field, which contains first name and sometimes middle initial.
Example: John P.
Mary J.
George
Sue
I use this expression to separate the middle initial into another field:
Middle Initial: IIf(InStr(InStr([TODAY].[FIRST NM],” “)+1,[TODAY].[FIRST NM],””)<>1,Right([TODAY].[FIRST NM],Len([TODAY].[FIRST NM])-InStr(InStr([TODAY].[FIRST NM],””)+1,[TODAY].[FIRST NM],” “)),””)

I can’t seem to get this to work to create a separate field for the first name. Help?!