COLOR CHANGE AND CONTINUAL TOTAL...EXCEL!!!!

Hello,


I am begging for help !!!!

I will explain what I need and then hopefully you can help me.

FIRST ISSUE:

If Cell F9 = E9 do nothing
If Cell F9 is less than or greater than E9 then turn the cell red

i need this to happen for 30 rows

do i put this in a cell outside of the data area? like in cell zz100?

SECOND ISSUE:

i want to have a running total for 30 rows of odometer readings in a blue box i created labeled "total mileage".

so 5-5-2010 reading 1000
5-6-2010 reading 1100
5-7-2010 reading 1350

what do i do to have it take 5-6-2010 minus 5-5-2010 and add it to 5-7-2010 minus m-6-2010?
I tried this =(b2-b1)+(b3-b2)+(b4-b3)
but i need this to be continues for 30 rows. so if row 5 is empty i only need the formula to add to that point.

please please help me :)