function getWidth() {
var windowWidth = 0;
if (document.documentElement && document.documentElement.clientWidth)
    windowWidth = document.documentElement.clientWidth;
else if (document.body)
    windowWidth = document.body.clientWidth;
if (windowWidth > 900)
    changeCSS ();
// alert(windowWidth); // delete the slashes at the beginning of this line for testing purposes
}
function changeCSS () {
// this function names the divs that will be resized. Change the names to the correct ones for your page and change the widths as needed. You can add as many named divs as you want. Just remember to change the name and width. Make sure you do not delete the single quote marks.
document.getElementById('containerDiv').style.width = '900px';
// document.getElementById('containerDiv').style.marginLeft = '5%';
// document.getElementById('containerDiv').style.marginRight = '5%';
document.getElementById('header').style.width = '900px';
document.getElementById('contentDiv').style.width = '888px';
document.getElementById('footerDiv').style.bottom = '0px';
// document.getElementById('headerfeatureDiv').style.left = '60%';
}