force option from <select> drop down before submit form - php

Question

I want the user to be forced to select any option in the drop down apart from the default "selected" option
here is my drop down menu code;
<form><label>Select Tank:</label>
<select class="text2" name="tank" id="mySelect">
<option value="0" selected="selected">Select your tank</option>
<option value="4"> Tank#1 </option>
<option value="9"> Tank#2 </option>
<option value="21"> Tank#3 </option>
<option value="34"> Tank#4 </option>
</select>
<input type="button" id="btncheck" value="Submit"/>
</form>
and here is my java;
$('#btncheck').click(function(){
if ($("#mySelect ")[0].selectedIndex <= 0) {
alert("Please select a tank from the menu!");
return false;
}
});
jsfiddle: http://jsfiddle.net/36JZL/41/
for some reason it validates correctly but form isnt submitted.

Answer 1

You can do it with jQuery on client side but its not a good option to validate things on client side.
PasteBin: http://jsbin.com/zer/1
<form id="myForm">
<label>Select Tank:</label><br />
<select class="text" name="tank" id="tankSelector">
<option value="All" selected="selected"> Select Tank </option>
<?QUERY HERE TO PULL AND LOOP FROM DATABASE?>
<option value="<?php echo $row->id; ?>"> <?php echo $row->description; ?> </option>
<? END LOOP ?>
</select>
<input type="submit">
</form>
<script>
$(function() {
$('#myForm').submit(function(e){
if($('#tankSelector').val() == 'All') {
alert('Select tank!');
e.preventDefault();
}
});
});
</script>

Answer 2

<label>Select Tank:</label><br />
<select class="text" id="seltank" name="tank">
<option value="All" selected="selected"> Select Tank </option>
</select>
in the client side click event of your submit button add some javascript to check the value of your drop down.
if(document.getElementById("seltank").value == "All")
{
//put some code to alert the user or show error
return false; //this should prevent your post
}
Similar post is here How do I cancel form submission in submit button onclick event?

Answer 3

Here's what I do:
<select class="text2" name="tank" id="mySelect">
<option></option>
<option value="4"> Tank#1 </option>
<option value="9"> Tank#2 </option>
<option value="21"> Tank#3 </option>
<option value="34"> Tank#4 </option>
</select>
If the user hits submit without making a selection, they will be prompted to select an option automatically. The limitation is that you don't get a pretty little "select an option" placeholder.

Answer 4

Maybe this can help. Im yet to find a stable answer
If using php:
$val = $_POST['select_input']; <--- works fine
or
$val = $request->select_input <---- can be problematic
On Html
<select id="select_input" name="select_input" >
<option value="0">Pending</option>
<option value="1">Approved</option>
<option value="0" selected>Pending</option>
</select>