Question

I need help in submitting a form with multiple dropdown with sames values,

conditions: if email is not selected alert email need to selected else check for value already selected

<form method="post" action="record_save.php">
    <div id="student_records">
        <select name="select1">
            <option value="0">None</option>
            <option value="1">email</option>
            <option value="2">firstname</option>
            <option value="3">lastname</option>
        </select>
        <select name="select2">
            <option value="0">None</option>
            <option value="1">email</option>
            <option value="2">firstname</option>
            <option value="3">lastname</option>
        </select>
        <select name="select3">
            <option value="0">None</option>
            <option value="1">email</option>
            <option value="2">firstname</option>
            <option value="3">lastname</option>
        </select>
        <!-- until -->
        <select name="select10">
            <option value="0">None</option>
            <option value="1">email</option>
            <option value="2">firstname</option>
            <option value="3">lastname</option>
        </select>
        <input type='submit' name='submit'>
    </div>
</form>

Answer 1

This should do what you want.

I iterate over the selected options and count how many times each occurs. On the first detection of a duplicate I add an error message. I also make sure an email was selected. If there are any errors we alert them otherwise the form gets submitted.

(function ($) {

    var form = $('#student_records').parent();

    form.submit(function (event) {

        event.preventDefault();

        var selected = {},
            errors = [];

        form.find('option:selected').each(function (index, elem) {

            var val = $(elem).val().trim();

            if (! selected[val]) {
                selected[val] = 1;
                return;

            } else if (selected[val] == 1) {

                errors.push('Already selected: ' + $(elem).text());
            }

            selected[val] += 1;
        });

        if (! selected[1]) {
            errors.push('Must select email.');
        }

        if (errors.length) {
            alert(errors.join("\n"));
            return;
        }

        form.submit();
    });

}) (jQuery);