Need to Create Error Message Box during Runtime error 1004

Hi guys,

I am using excel to product charts based on how many selections a user makes. i.e. if 5 brands are selected then the user clicks update graph, then the graph will relocate the range and update the graph.

Sub UpdateGraphs()

    ActiveSheet.ChartObjects("Chart 117").Activate
    ActiveChart.ChartArea.Select
    ActiveChart.PlotArea.Select
    ActiveChart.SetSourceData Source:=Sheets("GraphData").Range("A26:Indirect(B24)"), _
        PlotBy:=xlRows
            ActiveChart.ChartArea.Select
    ActiveChart.Legend.Select
    Selection.AutoScaleFont = False
    With Selection.Font
        .Name = "Arial"
        .FontStyle = "Regular"
        .Size = 6
        .Strikethrough = False
        .Superscript = False
        .Subscript = False
        .OutlineFont = False
        .Shadow = False
        .Underline = xlUnderlineStyleNone
        .ColorIndex = xlAutomatic
        .Background = xlAutomatic
    End With
    
    
End Sub

That is my what I have so far and it works fine, however if a user selects no brands and clicks update graph then I get the runtime error 1004, as the range becomes invalid, How can I create an error message pop up instead?

Any help would be great

Thanks,