Question : Excel hide a row with vba

if column 15 (O) has a Y in a row how can I hide the entire row. And then how can I unhide the row?
I have a sheet that column O either has a N or a Y in it. When I run a macro I want and row that has a Y in it to get hidden. Then I want to be able to unhide all rows that have a Y in column O.
There could be 5,000 rows
Thank You

Answer : Excel hide a row with vba

Ok, I figured it out, I had installed Source Gear's Vault (an older version) and that is what seems to caused the problem. I uninstalled it and it no longer throwing that error.