Need help with Macro to run on activated sheet

Hi All,

I have a workbook with multiple sheets that have similar data on similar fields. I recorded the macro on sheet 1 "ref", but does not run on any other sheets. How can I change it so that it runs on ANY sheet that's active.

thanks,

sjsfiji

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Sub Macro12()
'
' Macro12 Macro
' Macro recorded 4/17/2008 by andrew.carino
'
' Keyboard Shortcut: Ctrl+k
'
    Charts.Add
    ActiveChart.ApplyCustomType ChartType:=xlUserDefined, TypeName:="Gantt"
    ActiveChart.SetSourceData Source:=Sheets("Ref").Range("A1:G15"), PlotBy:= _
        xlColumns
    ActiveChart.SeriesCollection(2).Delete
    ActiveChart.SeriesCollection(2).Delete
    ActiveChart.SeriesCollection(4).Delete
    ActiveChart.Location Where:=xlLocationAsObject, Name:="Ref"
End Sub