OnLoad javascript AJAX呼叫

I need to create an onload event where an AJAX function is called and passed a value. I can't put it on body because I have both my header and footer cut in sections via PHP. Apparently I can't put this on a div and

    $(#midContainer).ready(function(){
        Change('value1');
    });

This doesnt seem to work and I am not sure why. I got an
"Uncaught SyntaxError: Unexpected token ILLEGAL"

Replace:

$(#midContainer).ready(function(){
    Change('value1');
});

with

$("#midContainer").ready(function(){
    Change('value1');
});

You are missing quotes around your DIV's Id

What is wrong with document.ready ?

$(function(){
   Change('value1');
})