Hallo,
Wie weist man einer Variablen ein Tabellenblatt zu?
Soweit bin ich:

Sub graph(Optional XY As String)

Dim ChrtObjts As ChartObjects, ChrtObj As ChartObject
Dim MyChart As Chart, ws As Variant 'Worksheet

Sheets(XY).Select

ws = ActiveSheet 'hier Fehler!

Set ChrtObjts = ws.ChartObjects
Set ChrtObj = ChrtObjts.Add(100, 100, 300, 700)
Set MyChart = ChrtObj.Chart
....

Gruß
Golem