Javascript functions not fetching data on load

Javascript functions not fetching data on load

I'm having an issue with the code I have provided below and I'm new to
Javascript and Jquery. What the code is supposed to do is on load it
fetches a number for "unread notifications" then places that number in a
div called notes_number. Then it should read the number from notes_number
and depending on if the number is more than 0 it will show the div called
notes_signal.
I do this on load, every 5 seconds, and then whenever the notifications
button is pressed. The code isn't working because on load it doesn't put a
number in the notes_number div. Also the other occurrences aren't working.
At one point I thought it was working but now I can't figure out what's
up. Here's the code:
//THIS IS TO CHECK WHEN THE PAGE COMES UP
$("#notes_number").load("getnumber.php");
if(document.getElementById("notes_number").innerHTML > 0){
var elem = document.getElementById("notes_signal");
elem.style.display = "";
}
if(document.getElementById("notes_number").innerHTML == 0){
var elem = document.getElementById("notes_signal");
elem.style.display = "none";
}
//THIS IS TO CHECK EVERY 5 SECONDS
window.setInterval(function(){
$("#notes_number").load("getnumber.php");
if(document.getElementById("notes_number").innerHTML > 0){
var elem = document.getElementById("notes_signal");
elem.style.display = "";
}
if(document.getElementById("notes_number").innerHTML == 0){
var elem = document.getElementById("notes_signal");
elem.style.display = "none";
}
}, 5000);
//THIS IS TO CHECK WHEN THE BUTTON IS PRESSED
function toggleDiv(divId) {
$("#"+divId).show();
$(document).ready(function(){
$("#myContent").load("getnotes.php?page=<? echo $page; ?>");
});
$("#notes_number").load("getnumber.php");
if(document.getElementById("notes_number").innerHTML > 0){
var elem = document.getElementById("notes_signal");
elem.style.display = "";
}
if(document.getElementById("notes_number").innerHTML == 0){
var elem = document.getElementById("notes_signal");
elem.style.display = "none";
}
}