How do I create a macro that allows me to show and hide rows with only one button?

[Davespil]

Hello, I would like to be able to click a button and unhide 10 rows. Then click the same button and have them hide those rows. I have the macro to unhide the rows, I just don't know how to make the same button hide them if they aren't hidden. Can anyone help me with that. My understanding of VBA is extremely limited. Thank you in advance. Here is my macro so far:

Sub MultiYear_Show()
'
' MultiYear_Show Macro
'
'
    Rows("10:20").Select
    Selection.EntireRow.Hidden = False
End Sub

[JKwan]

give this a go

Rows("10:20").EntireRow.Hidden = Not Rows("10:20").EntireRow.Hidden

[Davespil]

give this a go

Rows("10:20").EntireRow.Hidden = Not Rows("10:20").EntireRow.Hidden

It worked! Thank you.