If i load the checkboxes from database, and i uncheck the checkbox after submit it is still checked

The unchecking and checking after submit works if i don't use this line of code to load the data everything works. echo ($extraServices == 'Park') ? "checked='checked'" : (($extraServices == 'Park,Electricity') ?

<input type="checkbox" name="services[]" value="Park" <?php
echo ($extraServices == 'Park') ? "checked='checked'" : (($extraServices == 'Park,Electricity')  ? "checked='checked'" : "");
if(isset($_POST['services'])) {
    if(in_array("Park", $_POST['services'])) {
       echo "checked='checked'";
    }
}
?>> Park

So now if use echo "checked='checked'"; and echo ($extraServices == 'Park') ? "checked='checked'" : (($extraServices == 'Park,Electricity') ? "checked='checked'" : ""); together. It doesn't work. So with this code it will load the data from the database on which checkbox was checked. That works. But if i uncheck a checkbox it wont be unchecked after submit. How can i solve this? I thought about a way to detect if i load this page for the first time. But then i bumped into the problem that that was for loading the page the first time EVER.

I wanted to come up with something to detect if the page loads and loads the data. After that it doesn't need to load the data from the database. But i don't know how i could do this.

I dont know what to do now, hope that someone got some idea's?

Thanks for your help.