JavaScript负数下拉

Question

When I click "EDIT" link on a specific user it is suppose to tell me how many vacation days he/she has left... the Edit link is like this:

print "<a href=\"javascript:editUser('$data[uid]','$data[vacationdays]')\">Edit</a>\n";

So when i click EDIT on ADMIN account: javascript:editUser('Admin','-3.0') is the actual values

The javascript:

<script language="javascript">
    function editUser(uid, vacationdays) {
    document.userForm.uid.value = uid;
    document.userForm.vacationdays.value = vacationdays;
    document.location.href = "#AddEdit";
    }
</script>

The website PHP/HTML:

Vacation days: <select name="vacationdays" id="vacationdays" />
               <?php 
               for ($i=-30.5;$i<30.5;$i+=0.5)
               echo "<option value=\"$i\">$i</option>\n";
               ?>
               </select>

The problem is only with negative numbers (-1 or -2...etc) not showing up in the form pull down menu. Positive numbers show up no problem.

Example positive number:

Example negative number:

**** i dont want to be able to select a negative values from the pull down.. but if the value is negative i just want it to show once and when you click on the pull down you can only select positive numbers ****

If i change the pulldown to a TEXTFIELD it works perfectly fine with negative numbers...weird?

Answer 1

Just add the negative numbers to your list :

function vacationdays_list() {
    for ($i=-30.5; $i<30.5; $i+=0.5)
        echo "<option value=\"$i\">$i</option>\n";
}

Answer 2

generate list for negative number between -30.5 till 0

 for ($i=-30.5;$i<0;$i+=0.5)
    echo "<option value=\"$i\">$i</option>\n";

generate list for number between -30.5 till +30.5

 for ($i=-30.5;$i<30.5;$i+=0.5)
    echo "<option value=\"$i\">$i</option>\n";

if you want always selected be a positive number you can use Absolute abs() http://php.net/manual/en/function.abs.php in php or Math.abs in JavaScript

generate list for number between -30.5 till +30.5 that negative number is disabled

for ($i=0;$i<30.5;$i+=0.5)
    echo "<option value=\"$i\" >$i</option>\n";  
for ($i=-30.5;$i<0;$i+=0.5)
    echo "<option value=\"$i\" disabled>$i</option>\n";

edit:

 Vacation days: <select name="vacationdays" id="vacationdays" />
           <?php 
           for ($i=30.5;$i>0;$i-=0.5)
              echo "<option value=\"$i\" >$i</option>\n";  
           for ($i=0;$i>-30.5;$i-=0.5)
              echo "<option value=\"$i\" disabled>$i</option>\n";  
           ?>
           </select>   

Answer 3

You don't need to echo your function, so it should be

Vacation days: <select name="vacationdays" id="vacationdays" />
               <?php vacationdays_list(); ?>
               </select>

and for negative numbers

function vacationdays_list() {
    for ($i=-30.5; $i<30.5; $i+=0.5)
        echo "<option value=\"$i\">$i</option>\n";
}