Copying Given Row To The Next Worksheet

In Sheet1, I have this:


Nos. Items Enter Qty

1 Item1 5
2 Item2
3 Item3 20
4 Item4 50
5 Item5
6 Item6 3
etc...

What I want is, whenever I enter the quantity in Sheet1 it will copy the row in Sheet2, say it will start in row 5 without the blank row and it is something like this:

Sheet2


Nos.Items Enter Qty

1 Item1 5
3 Item3 20
4 Item4 50
6 Item6 3
etc...