Adding error message when a specific drop down option is selected - php

Question

Ok guys, Ive done some researching and can't find something that works to solve my problem even though I'm sure its a simple fix :)
I have a simple contact form in which the first line is a drop down selection. This drop down determines which employee the form is submitted to. I just want to make my default option of "Please Select Category" return an error message so that the submitter must go back and select one of the options to get the form sent. When nothing is selected, its creating a lot of junk mail to the default email.
Here is the drop down bit of code:
<tr>
<td><label for="sendTo">Category (required):</label></td>
<td>
<select id="sendTo" name="sendTo">
<option id="pleaseSelectcategory1" value="pleaseSelectcategory1">Please Select Category</option>
<option id="aftermarketCustomerservice" value="aftermarketCustomerservice">Aftermarket Customer Service</option>
<option id="technicalAssistance" value="technicalAssistance">Technical Assistance</option>
<option id="aftermarketSales" value="aftermarketSales">Aftermarket Sales</option>
<option id="performanceProducts" value="performanceProducts">Performance Products & Sales</option>
<option id="oemSales" value="oemSales">OEM Sales</option>
<option id="exportSales" value="exportSales">Export Sales</option>
<option id="generalFeedback" value="generalFeedback">General Feedback</option>
</select>
</td>
</tr>
I just need what to put in my html, if anything, to make this error message occur and in my php file. Thanks in advance!!

Answer 1

You should use a Javascript function to validate your form prior to posting the data. This is better for UX, and will prevent the form from even reaching the PHP post function.
In your form have the onsubmit field call a Javascript function:
<form name="form" id="form" action="" onsubmit="return validateForm()" method="POST">
and your Javascript function for checking the select box value:
// Basic form validation for select box.
function validateForm() {
if (document.getElementById("sendTo").value != null && docmument.getElementById("sendTo").value != "pleaseSelectcategory1") {
return true;
}
//Handle error message here.
alert("Please select a category");
return false;
}
You can also validate your form once the form gets posted in PHP with:
if ($_POST['sendTo'] === 'pleaseSelectcategory1') {
// Redirect back to form or do whatever
}

Answer 2

In pure JavaScript you can use the following function:
function checkCategory(){
if(document.getElementById('sendTo').value === 'pleaseSelectcategory1') {
alert("You need to select category");
//This is to ensure that the form doesn't get submitted.
return false;
}
}
Either use onclick="javascript:checkCategory();" on the button or the form itself onsubmit="javascript:checkCategory();"
In PHP you can just use:
if($_POST['sendTo'] == "pleaseSelectcategory1")
{
//However you want to handle the the fact the user selected the option
}