Macro For Picking Out Trends In Data

I am trying to write a macro that will automate the process of selecting rows from a data sheet. I want the rows to be selected based on the values in two columns. I want to find and select the row at the beginning and end of positions in a column where the values are equal. For a quick example, if my data looks like this below, I'd want to select the entire row for rows 2,3, and 6... I also need the row just before the value in both columns are equal.

row column11 column12
1 0 1
2 0 1
3 1 1
4 1 1
5 1 1
6 1 1
7 0 1
8 0 1

I have written this macro and it is not working... are there any obvious problems with this? This is new to me and I'm not exactly sure that I've used the correct commands. It also seems like LastRow is referencing 0 and not 12965 or whatever the last row of filled data is for the sheet.

Sub Deltadata()
Dim RowNum As Long, LastRow As Long
LastRow = Range("A" & Rows.Count).End(xlUp).Row
'Finds last filled row (should be 12965)

For RowNum = 3 To LastRow Step 1

[Code] ........