Remov Blank Cel Frm Col A & Hav 2 rite in B

Hello,

I need to remove blank cell from column A & need to write in Column B.
With out disturbing the Column A alone (Coz To populate data in Col A i'm using some formula).

I used a macro ,

Private Sub Worksheet_Calculate()

Range("A1:A250").Select
Columns(1).SpecialCells(xlCellTypeBlanks).EntireRow.Delete

End Sub

But this is deleting entire row ,
I have some formula in that Col A , So it's running like infinite loop too.

Ex.
Col A Col B Col C
------- ------- --------
A --------------- 1
----------------- 1
B --------------- 1
----------------- 1
C--------------- 1
D--------------- 1
E--------------- 1

After Macro , I need ,

Col A Col B Col C
------- ------- --------
A ------ A ------ 1
---------- B ------ 1
B ------ C ------ 1
----------- D ------ 1
C ------ E ------ 1
D ------
E ------