hello everyone

imagine..i have:
- textbox1(control source = a1)
- textbox2(control source = a2)
in cell a3 i´ve got =sum(a1:a2),what i want was that
- textbox3(control source = a3), but if i did that i overwrite the function
sum

is possible that i have the textbox3 with the sum value wythout type code,
just link it to a cell.

thanks in advance
Miguel