Calculating values from different sheet

Hi All,

Straight to the point!!

I have a workbook with 3 sheets each having 2 columns!

Sheet1:

Col-A	Col-B
3245688	12
4567893	13.5
1342567	15

Sheet2:
Col-A	Col-B
3245688	13.7
2139475	45
9875768	23

Sheet3:
Col-A	Col-B
142234	23
24563	56
156789	13.2

Now i need to search in all 3 sheets, if column A value of one sheet matches with another sheet, then i need to sum the values in column B. if it doesnot matches then i just need take those values and put it in my resultant sheet.

so the result from the above example will be as below:

Col-A	Col-B
3245688	25.7
4567893	13.5
1342567	15
2139475	45
9875768	23
142234	23
24563	56
156789	13.2

Since here the first value in column A of sheet 1 matches with that of sheet 2, the values in column B is summed up.. all other values are placed as it is..

Thank you,