IF Statement to input initials

[peg84]

I have a spreadsheet where I have the first name in the first column
then the last name in the next column. I am inserting a new column fo
the last initial. What I want is to leave the cell blank if I do no
have the last name but, if I do, insert the first letter of the las
name along with ".". The formula I have it =IF(B1=" ",
",((LEFT(B1,1)&"."))). It does put the first letter and "." in th
cell but will not leave blank if no last name. Any idea what I a
doing wrong

 

[Gary''s Student]

=IF(B2="","",LEFT(B2,1) & ".")


No space between the first pair of double quotes

 

[peg84]

I knew it had to be something simple! Thank you very much for your
help.