I have a sheet that when opened, populates it's data via vlookups and opens 4 more sheets for updating purposes.

Currently, if I already have any of those 4 sheets open, the macro breaks. What I would like to be able to do is have the main sheet run it's macro and if it sees that the sheet it's trying to open, is already open, skip it and continue on to the next one.

I tried the help files but came up wanting. Any help would be appreciated.