PHP： - 在newtab中通过POST验证并传递值

Question

Below code is about passing the value to the new tab by POST.

My question is the value selected in drop-down list needed to be validated.

As 'select' value is default value. If the default value is selected then some alert must be shown else the remaining behavior is same as below code.

<form action="send_mail.php" name="choose_aff" method="POST">
<select name="company" id="company" class="company_select" style="width:250px;">
<option value="">Select</option>
<option value="abc">abc</option>
<option value="xyz">xyz</option>
</select>
<input class="proceed_btn" type="submit" value="Proceed to mail>>" style="float:right" onclick="this.form.target='_blank';return true;">
</form>

Answer 1

I remove a button and then the send_mail.php will open only when value is changed from dropdown. Add dropdown will send value using POST

<form action="send_mail.php" name="choose_aff" method="POST">
    <select name="company" id="company" class="company_select" style="width:250px;" onchange="submit()">
    <option value="">Select</option>
    <option value="abc">abc</option>
    <option value="xyz">xyz</option>
    </select>
    </form>