I'm trying to reduce the space between the page content and the footer..this is the code i'm using to resize and the method call is implemneted in master page pageload()

function resize() {
    var windowHeight;
    if (document.getElementById("leftnav") && document.getElementById("content")) {
//         document.getElementById('leftnav').style.height = document.getElementById('content').offsetHeight - 20 + 'px';
        if (document.getElementById("content").offsetHeight >= 698) {
                        document.getElementById("leftnav").style.height = document.body.clientHeight + "px";
                        document.getElementById("content").style.height = document.body.clientHeight + "px";
This method resizes based on the content but it gives more extra space between the content and the footer which is not our site standards. Any suggestions please?