Selecting and deleting named range based on cell value

I'm using a count function to return a value to cell M5.

I am trying to figure out the VB code to use that value to delete a named range based on the following:

If M5 <20 delete range4
If M5 >20 but <41 delete range3
If M5 >20 but <61 delete range2
If M5 >20 but <81 delete range1

I got it I think:

If Range("m5").Value < 21 Then Range("page2").Delete
else
...