Clear select option after successful submit - php

Question

<div class="select_list">
<div class="labels">Category:</div>
<?php
if(!isset($_POST['postbtn)){
echo "<script>$(document).ready(function(){
$('.category').val(0);
})
</script>";
}
echo "<select name='category' id='catg_list' class='list_catg'>
<option value='0'";
if(isset($_POST['category']) && $_POST['category']=='0'){
echo "selected";
}
echo">none</option>";
$query = mysql_query("SELECT id, name from table1");
while($query_fetch = mysql_fetch_assoc($query)){
echo "<option value='".$query_fetch['id']."'";
if(isset($_POST['category']) && $_POST['category']==$query_fetch['id'])
{
echo "selected";
}
echo ">".$query_fetch['name']."</option>";
}
echo "</select>";
?>
</div>
The problem with the above code is that the selected element stays selected after the submission is done. I need the select option to return back to 'none' when the form is submitted successfully. How can that be done?

Answer 1

You have an syntax error in your line:
if(!isset($_POST['postbtn)){
change it to:
if(!isset($_POST['postbtn'])){
I'm guessing some things you didn't mention:
You validate your script above the code you posted, and you want - if the script was validated successfully - that the "none" option is selected.
$selected_value = $validation ? $_POST['category'] : false;
Only if the Validation is correct the value will be set, else it will be set to false;
<?php
echo "<select name='category' id='catg_list' class='list_catg'>
<option value='0'";
//CHANGE
if($selected_value == 0){ //Or if($selected_value === FALSE ||$selected_value === 0)
echo "selected";
}
echo">none</option>";
$query = mysql_query("SELECT id, name from table1");
while($query_fetch = mysql_fetch_assoc($query)){
echo "<option value='".$query_fetch['id']."'";
//CHANGE
if($selected_value !== FALSE && $selected_value == $query_fetch['id'])
{
echo "selected";
}
echo ">".$query_fetch['name']."</option>";
}
echo "</select>";
?>

Answer 2

Simplify your code as following to do required task.
$category = isset($_POST['category']) ? $_POST['category'] : 0;
$array["0"]="none";
$query = mysql_query("SELECT id, name from table1");
while($query_fetch = mysql_fetch_assoc($query)){
$id = $query_fetch['id'];
$array[$id] = $query_fetch['name'];
}
echo "<select name='category' id='catg_list' class='list_catg'>";
foreach($array as $id=>$name) {
$selected = $category==$id ? "selected" : "";
echo "<option value='".$id."' ".$selected." >".$name."</option>";
}
echo "</select>";