Fill in empty cell in data.frame from previous value

Hello Total newbie here... I hope I read the guide properly

I have the following data.frame (I read it from a CSV file I cannot change)

  names val
1 Mandy   1
2         2
3 John    2
4         2

I want to read the row number 2, but I want the first column to be ?Mandy? and not null

print (frame[2,])
2 Mandy   2

I can manipulate the data.frame once loaded
How can I fill all cell in column ?names? with the previous value ?
Or is there a function that will get me the row and fill the ?names? column ?

NOTA BENE: I do not want the answer, I want to find it myself but I need guidance
If there is a function, tell me the library and I will search
If this is an algorithm, tell me generally how you would do and let me scratch my head first ?

Thanks Chris