Hide or Unhide Rows on one sheet based on value entered in cell on another sheet

Greetings folks,
I have a work book and on Sheet 1 Cells A1, A2, A3, A4 are blank, but if a user puts in a value in A1, I would like it to unhide Rows 1-5 on sheet 2, and if user clears A1 on sheet 1, I would like rows 1-5 on sheet 2 to be hidden again. If users puts entry in A2 on Sheet 1, I would like it to unhide rows 6-10 on sheet 2 and if they clear the value in A2, I would like it to rehide rows 6-10

Right now users have to add and remove rows or copy and paste information to notepad to change values. The user can have 4 chioces A1 - A4 and each entry will have some cells that start out hidden on sheet 2. If they add an entry it will unhide them. If they clear entry it will rehide them.

I hope this makes sense.

We have a spreadsheet that our engineers use to generate a configuration script they they copy and paste into devices to configure them. Being able to create the whole spreadsheet and have certain rows hidden or unhidden based on values they place on the variables sheet (sheet 1 from example above) would be a great addition to our existing spreadsheet.

Thanks in advance for any assistance you can provide.

Wally