更新MultiSelect下拉列表

Question

My webpage works like this:

I have a multiselect dropdown that is populated by two database tables. The one table has all of the values and the other has the selected values. (This part cannot be changed)

Once the dropdown is populated and the correct values are selected, the user then has the option to select more values in the list and that would transfer in an array to another page.

function getGrade($id, $grades_array)
{
        $counter = 0;
        $sql = "Select grade FROM grades";
        $result = mysql_query($sql) or die (mysql_error());
        echo '<select name="grade" multiple="multiple" id="grades_selected">';
        while ($row = mysql_fetch_array($result)) {

                if ($row['grade'] != $grades_array[$counter]) {
                        echo "<option>" . $row['grade'] . "</option>";
                } else {
                        echo "<option selected=" . $row['grade']  . ">" . $row['grade'] . "</option>";
                        $counter = $counter + 1;
                }
        }
    mysql_free_result($result);
        echo '</select>';
}

The initial variable $grades_array is the selected values.

In words the solution I need is to be able to pull the values from the database on page load but if the user selects more values then it will be able to add those to the array and save that variable to use on the other page. The hardest part I think is then when the user comes back to the page for the 2nd time it does not pull from the database again and uses the same created variable to populate the dropdown.

Someone Please Help!

Answer 1

You can try this by using this AJAX, easier to do rather than doing it with PHP

suggestion text field like -- google suggestion - using AJAX/Jquery