Selecting all rows with the same ID number, then iterating - VBA - excel

Question

I have a sorted list of ID's in Excel. I want to grab all the rows with the same ID, then I'll be manipulating them.
Sub Selectingabox()
Dim I As Integer
Dim N As Integer
'Defining
I = 1
N = 1
'Initializing
While I < 3000
'If I have more than 3k rows I'm in serious trouble anyways
If Range("A" & I).Select = Range("A" & I + 1).Select Then
I = I + 1
Else: Range("A" & N, "AJ" & I).Select
'Lots of stuff manipulating the data range we just selected
N = I + 1
'The new top row
I = I + 1
'The new bottom row
Wend
End Sub
Not quite working.. the wend is unhappy with me, and I'm not sure why. Also have no idea if the code will work!

Answer 1

Couple of things:
dim your values as long rather than integer, so you won't get an error at row 32k
Use a FOR loop rather than a while loop to make your code more efficient
Rather then using number 3000 you can use VBA to find the last row automatically using Cells(Rows.Count, "A").End(xlUp).Row
I would not recommend using .Select in your code. What are you trying to manipulate?
Sub Selectingabox()
Dim I As Long
Dim N As Long
Dim lastrow As Long
lastrow = Cells(Rows.Count, "A").End(xlUp).Row
N = 1
For I = 1 To lastrow
If I = lastrow Then
If Range("A" & I).Value <> Range("A" & I - 1).Value Then
Range("A" & N & ":AJ" & I).Select
N = I + 1
End If
Else
If Range("A" & I).Value <> Range("A" & I + 1).Value Then
Range("A" & N & ":AJ" & I).Select
'Lots of stuff manipulating the data range we just selected
N = I + 1
End If
End If
Next I
End Sub

Answer 2

Add an End If into your code - that will resolve the Compile Error
Sub Selectingabox()
Dim I As Integer
Dim N As Integer
'Defining
I = 1
N = 1
'Initializing
While I < 3000
'If I have more than 3k rows I'm in serious trouble anyways
If Range("A" & I).Select = Range("A" & I + 1).Select Then
I = I + 1
Else: Range("A" & N, "AJ" & I).Select
'Lots of stuff manipulating the data range we just selected
N = I + 1
'The new top row
I = I + 1
'The new bottom row
End If ' add this here
Wend
End Sub