Copy Cells down the column

I have two columns of data, say column A and B. I would like to have a macro that copies the data on Cell B1 down the column where there is data in column A.


Col A Col B
343 ABC
46
335
312
345

Thanks for your helps....

NBVC,

If the data in Cell B1 is a formula, the macro just copies the value of the cell down the column, instead of the formula. How can I modify the script in order to copy the formula down the column.

Thanks...