How to get variables in first open cell

I'm trying to do is get three variables (name, score, grade) in columns A, B, and C respectively. I dimmed name as string, score as double, grade as string, and i as long. The first part takes input for name and score and determines grade based on numerical score.

I think this code snippet caused Excel to crash. If so then why?

For i = 1 to Rows.Count
     If IsEmpty(Cells(i,1)) = true then Cells(i,1) = name
     Next i

For i = 1 to Rows.Count
     If IsEmpty(Cells(i,2)) = true then Cells(i,2) = score
     Next i

For i = 1 to Rows.Count
     If IsEmpty(Cells(i,3)) = true then Cells(i,3) = grade
     Next i