Re: Warning: Division by zero

Thanks for your response. The error I am getting is when I am defining a variable. (line 15) $percent_difference=($assess_difference)/($assess_value); Does this make a difference? Thanks again for all your help. Gary "Christoph Boget" <christoph.boget@gmail.com> wrote in message news:540509760904300600i7af94667w6bad30ed068d1937@mail.gmail.com... >> I have a script that is a result of data entered in a form >> On the script (when I test without data entry), I am getting a warning >> that >> Warning: Division by zero in .inc.php on line 15. >> The warning is correct, however the viewer cannot access the second >> script >> without entering the data that would cancel the warning. >> Is this something I should worry about? or would it be better to right in >> an >> isset? > > Well, just as a general rule, you'll want to validate all possible > user input. That includes checking whether or not particular input > has been defined, whether or not it is valid for it's intended use and > whether or not it's malicious. > > Applying that guideline to your situation, I would check to see if: > > * the input is set > * the input is numeric > > If either or those are not true, I would default the value to 1 since > division is being used. e.g., > > $iVar = 1; > if(( isset( $_REQUEST['MY_NUMBER'] ) && ( is_numeric( > $_REQUEST["MY_NUMBER']))) { > $iVar = $_REQUEST['MY_NUMBER']; > } > > $iCalculatedValue = $x / $iVar; > > thnx, > Christoph