//Sizes the main content div when browser windows changes/loads
function DisplayContentDiv() {
    var MIN_CONTENT_HEIGHT = 260;

    //get elements
    var header = 356;
    var footer = 40;

    //get height of window
    var height = document.viewport.getHeight();
    height = height - header - footer;

    //set div height
    if (height < MIN_CONTENT_HEIGHT) {
        height = MIN_CONTENT_HEIGHT;
    }

    $('iFrameDiv').style.height = height + 'px';
    $('iFrameDiv').style.zIndex = 1;    
}

Event.observe(window, 'load', DisplayContentDiv);
Event.observe(window, 'resize', DisplayContentDiv);