Macro Button of products that adds the selected product into order list

HansVogelaar 
I get the following error: Compile error: User-defined data type not defined

And it will mark the following yellow : Dim r as Row.

If i try a different data type, like Range it will give: objectvariable or blockvariable with not defined.

So i tried the following: 
Sub WashPlate1()
Dim r As Range
Set r = Range("H80").End(xlUp)
If r >= 80 Then
MsgBox "Geen ruimte meer!", vbCritical
Else
Range("H" & r + 1).Value = "Wash Plate 1"
End If
End Sub

With the code above i get the "Geen ruimte meer" msg. Only nothing will be added, and there is still place left.

if i change the code to: 

Sub WashPlate1()
Dim r As Range
Set r = Range("U80").End(xlUp)
If r >= 80 Then
MsgBox "Geen ruimte meer!", vbCritical
Else
Range("U" & r + 1).Value = "Wash Plate 1"
End If
End Sub

The code works, probably because column U is completely empty:

But the question now is, How can i make sure this happens within "H". And also if i click again, i will get the msg "Geen ruimte" again and i can't seem to get wash plate 1 in the cell beneath "U1". 

Like this:

Wash plate 1
Wash plate 1

Could you help me further?