function getWindowHeight() {
    var windowHeight=0;
    if (typeof(window.innerHeight)=='number') {
        windowHeight=window.innerHeight;
    }
    else {
     if (document.documentElement&&
       document.documentElement.clientHeight) {
         windowHeight = document.documentElement.clientHeight;
    }
    else {
     if (document.body&&document.body.clientHeight) {
         windowHeight=document.body.clientHeight;
      }
     }
    }
    return windowHeight;
}

function setFooter() {
	if (document.getElementById) {
		var windowHeight=getWindowHeight();
		if (windowHeight>0) {
			
			var headerHeight = document.getElementById('header').offsetHeight;
			var solutionHeight = document.getElementById('solution').offsetHeight;
			var contentHeight = document.getElementById('contenu').offsetHeight;
			var total = headerHeight + solutionHeight + contentHeight;
			
			var footerElement = document.getElementById('footer');
			
			var footerHeight = footerElement.offsetHeight;
			if (windowHeight-(total+footerHeight)>=0) {
				footerElement.style.position='relative';
				footerElement.style.top = (windowHeight-(total+footerHeight))+'px';
			} else {
				footerElement.style.position='static';
			}
		}
	}
}

window.onload = function() {
	setFooter();
}
window.onresize = function() {
	setFooter();
}