using array push in jquery by accessing php array variable - php

Question

this is my php code:
if (($_SERVER["REQUEST_METHOD"] == "POST")&&(isset($_POST["btn_save"]))) {
$schoolsInput=$_POST['schoolsInput'];
echo $schoolsInput[0];
}
this is my jquery code:
<script type="text/javascript">
$(document).ready(function()
{
var counter=1;
var max_fields=5;
var add_button = $("#btn_addTxt");
var save_btn= $("#btn_save");
var wrapper= $("#prevSchoolTable");
$(add_button).click(function(e){
e.preventDefault();
if (counter == max_fields) {
alert("You have reached the limit of adding " + counter + " inputs");
}
else {
$(wrapper).append('<tr><td><input type="text" name="schoolsInput' + counter + '" id="schoolsInput' + counter + '" class="textbox" style="width:400px;">'
+ '</td></tr>');
counter++;
}
});
var arrayFromPHP = <?php echo json_encode($schoolsInput); ?>;
$("#btn_save").click(function () {
var msg = '';
for(i=1; i<counter; i++){
msg += "\n " + $('#schoolsInput' + i).val();
}
alert(msg); \\array push must go here
});
});
</script>
I've search how can i access PHP variable and they say to use:
var obj = <?php echo json_encode($schoolsInput); ?>;
But everytime i put this on my jquery, the ADD function is not working.
any suggestion?