I'm looking for a way to hide specific sheets based on the value in a specific cell. Here's what I want:

Let's say I have 4 Sheets called Main, Sheet2, Sheet3, and Sheet4. On the sheet titled Main, I have a drop-down menu containing the choices A, B, and C in cell B1.
If B1 on Main is blank, I want Sheets 2-4 to be hidden.
If B1 on Main contains A (selected from the drop-down menu, not entered manually), I want Main, Sheet3, and Sheet4 to become hidden.
If B1 on Main contains B (selected from the drop-down menu, not entered manually), I want Main, Sheet2, and Sheet4 to become hidden.
If B1 on Main contains C (selected from the drop-down menu, not entered manually), I want Main, Sheet2, and Sheet3 to become hidden.

I know it would be much simpler to use a macro and have to enter the value manually, but I'm willing to invest extra time to have it this way. Well, invest time and ask for help.

If it's absolutely not possible, what would be the macro to have this happen when the value in B1 is entered manually? I've tried it myself but I can't seem to make it work. Even when the code doesn't return any errors, I've just made a useless string that doesn't do anything. I'm sure it's something stupid I'm leaving out. Ideas?