Dim i as Integer
Dim Summ as Integer
''''''''''''''''''''''''''''''''''''
Summ=1
For i=-10 to 10 Step 2
Summ=Summ*i
Next
'''''''''''''''''''''''''''''''''
i=-10
Summ=1
Do
summ = summ * i
i = i + 2
Loop While i <> 12
''''''''''''''''''''''''''''
i=-10
Summ=1
Do
summ = summ * i
i = i + 2
Loop Until i = 12