Runtime error '9' - Hiding worksheets based on cell value.

[hludwig]

I'm relatively new to this, and its entirely possibly (more likely probable) that I am attempting to this in the wrong way, but here's what I'm dealing with...

Private Sub Worksheet_Change(ByVal Target As Range)
 If Me.Range("i2").Value = "" Then
     Worksheets(Range("a2").Value).Visible = xlSheetHidden
 Else
     Worksheets(Range("a2").Value).Visible = xlSheetVisible
 End If
 
 If Me.Range("i3").Value = "" Then
     Worksheets(Range("a3").Value).Visible = xlSheetHidden
 Else
     Worksheets(Range("a3").Value).Visible = xlSheetVisible
 End If

 If Me.Range("i4").Value = "" Then
     Worksheets(Range("a4").Value).Visible = xlSheetHidden
 Else
     Worksheets(Range("a4").Value).Visible = xlSheetVisible
 End If

 If Me.Range("i5").Value = "" Then
     Worksheets(Range("a5").Value).Visible = xlSheetHidden
 Else
     Worksheets(Range("a5").Value).Visible = xlSheetVisible
 End If

 If Me.Range("i6").Value = "" Then
     Worksheets(Range("a6").Value).Visible = xlSheetHidden
 Else
     Worksheets(Range("a6").Value).Visible = xlSheetVisible
 End If

 If Me.Range("i7").Value = "" Then
     Worksheets(Range("a7").Value).Visible = xlSheetHidden
 Else
     Worksheets(Range("a7").Value).Visible = xlSheetVisible
 End If

 If Me.Range("i8").Value = "" Then
     Worksheets(Range("a8").Value).Visible = xlSheetHidden
 Else
     Worksheets(Range("a8").Value).Visible = xlSheetVisible
 End If

 If Me.Range("i9").Value = "" Then
     Worksheets(Range("a9").Value).Visible = xlSheetHidden
 Else
     Worksheets(Range("a9").Value).Visible = xlSheetVisible
 End If

... repeated til....

 If Me.Range("i150").Value = "" Then
     Worksheets(Range("a150").Value).Visible = xlSheetHidden
 Else
     Worksheets(Range("a150").Value).Visible = xlSheetVisible
 End If
End Sub

I keep getting a runtime error 9 and the debugger takes me to "Worksheets(Range("a7").Value).Visible = xlSheetHidden." even if I can get it to accept this line, it'll just move the next one... what am I doing wrong? It seemed pretty straightforward. A7 does contain a reference (100027, its an account number) and there is a worksheet with the same name. I have verified this over and over. The code works if i only do the first 6, but once I get past 7, it wont function. Is there a better way to do what I'm attempting or at least a way to fix this? What am I doing wrong? This is rather frustrating...