How to combine two Excel sheets by removing blank rows automatically ?

I am making two sheet's data in once, for example, In Sheet1's cell reference as follows : cell A1 =Sheet2!A1, cell A2=Sheet2!A2,cell A3 =Sheet3!A1,cell A4 =Sheet3!A2,cell B1 =Sheet2!B1,cell B2 =Sheet2!B2,cell B3 =Sheet3!B1, cell B4 =Sheet3!B2. And now if i put the data's or numbers in SHEET2 (4 cells) and SHEET3 (4 cells) totally 8 cells reference will be refelects in SHEET1 as by above typed formula, Now if i delete or leave blank the rows of SHEET2 cells as follows: =Sheet2!A1 and =Sheet2!B1 both deleted or leaved blank then SHEET1 refernce should automatically hide or disappear and if i again insert the numbers or data in =Sheet2!A1 and =Sheet2!B1 then cell value should be reappear, A very helpful to me if anybody helps me on this problem, also thanks in advance to resolve this problem.