ASP result invalid result in equation

An invalid results from a simple calc

It's code:
while not rs.eof
wvl_lanc_atu_tro = rs("vl_lancamento")
response.write "<br>*** Start Calc ***"
response.write "<br>From: " & wvl_saldo_tro_atu & " Plus: " & wvl_lanc_atu_tro
wvl_saldo_tro_atu = wvl_saldo_tro_atu
wvl_saldo_tro_atu = wvl_saldo_tro_atu + wvl_lanc_atu_tro
response.write "<br>New result: " & wvl_saldo_tro_atu
response.write "<br>Result to write: " & wvl_saldo_tro_atu
response.write "<br><br>"
rs.fields("vl_saldo") = wvl_saldo_tro_atu
rs.update
rs.movenext
wend

Processing:

*** Start Calc ***
From: 0 Plus: 0,31
New result: 0,31
Result to write: 0,31


*** Start Calc ***
From: 0,31 Plus: 92,78
New result: 93,09
Result to write: 93,09


*** Start Calc ***
From: 93,09 Plus: -96,39
New result: -3,300003
Result to write: -3,300003 ===> Correct is 3,3


*** Start Calc ***
From: -3,300003 Plus: 1,25
New result: -2,050003
Result to write: -2,050003


*** Start Calc ***
From: -2,050003 Plus: 0,05
New result: -2,000003
Result to write: -2,000003


*** Start Calc ***
From: -2,000003 Plus: 2
New result: -3,099442E-06
Result to write: -3,099442E-06

What is happening???????

 

try adding the highlighted line:

while not rs.eof
wvl_lanc_atu_tro = rs("vl_lancamento") 
response.write "<br>*** Start Calc ***"
response.write "<br>From: " & wvl_saldo_tro_atu & " Plus: " & wvl_lanc_atu_tro
wvl_saldo_tro_atu = wvl_saldo_tro_atu 
wvl_saldo_tro_atu = wvl_saldo_tro_atu + wvl_lanc_atu_tro
[B][COLOR="Red"]wvl_saldo_tro_atu = FormatNumber(wvl_saldo_tro_atu, 2)[/COLOR][/B]
response.write "<br>New result: " & wvl_saldo_tro_atu
response.write "<br>Result to write: " & wvl_saldo_tro_atu
response.write "<br><br>"
rs.fields("vl_saldo") = wvl_saldo_tro_atu
rs.update
rs.movenext 
wend

Code (markup):

 

It rounds the result to 2 decimal points

 

The problem is not ROUND.
Operation:
wvl_saldo_tro_atu = 93.09
wvl_lanc_atu_tro = -96.39
instruction: wvl_saldo_tro_atu = wvl_saldo_tro_atu + wvl_lanc_atu_tro
Then 93.09 + (-96.39) = -3.3 but result is -3.300003

93.09 - 96.39 = 3.3 The result 3.300003 is impossible.It's an error, not round problem.

Only with some values the problem ocours.

Database is Ok, I think. The problem occurs before update DB.
If you want to download DB and ASP source code to test yourself: conectafarma.com/cf/downloads/DBtest.zip

I'm running in IIS 5.1, but in others servers the problem persists.

Please Help!!!!

 

Hi,
Looking at the files you provided me the problem is within the database...
Your fields: vl_lancamento AND vl_saldo ... are of set to type 'Single', and decimal places Auto (which must round to 2)... Go into design view of the table and change the 'Field Size' of these fields to 'Double'....

Now view the contents of your table:
the first is : 0.310000002384186
second is: 92.7799987792969
etc. etc.

This is what is causing the problem... either change the values of the table or round the values as you calculate.