var zoom = 100


function getElementsByClass(searchClass, node, tag) {
	var classElements = new Array();
	if ( node == null ) 
	    node = document; 
	if ( tag == null ) 
	    tag = '*';
	var els = node.getElementsByTagName(tag);
	var elsLen = els.length;
	var pattern = new RegExp("(^|\\s)"+searchClass+"(\\s|$)");
	for (i = 0, j = 0; i < elsLen; i++) 
	{
		if ( pattern.test(els[i].className) ) 
		{
			classElements[j] = els[i];
			j++;
		}
	}
	return classElements;
}

function zoomIn () {
    if (zoom <= 132) 
        zoom = zoom + 8;
    doZoom();
}


function zoomOut () {
    if (zoom > 100) 
        zoom = zoom - 8;
    doZoom();
}

function doZoom () {
	a = document.getElementById("conteneur");
    b = getElementsByClass("col_centre", a);
    
    for (i = 0; i < b.length; i++) {
    	if (zoom <= 100){
    		b[i].style.fontSize = "";
    	}
    	else {
    		b[i].style.fontSize = zoom+"%";
    	}        
        /*cibles = b[i].getElementsByTagName("*");
        for (j = 0; j < cibles.length; j++) {
            cibles[j].style.fontSize = zoom+"%";
        }*/
    }
    
    b = getElementsByClass("col_droite", a);
        
    for (i = 0; i < b.length; i++) {
    	if (zoom <= 100){
    		b[i].style.fontSize = "";
    	}
    	else {
    		b[i].style.fontSize = zoom+"%";
    	}
        /*cibles = b[i].getElementsByTagName("*");
        for (j = 0; j < cibles.length; j++) {
            cibles[j].style.fontSize = zoom+"%";
        }*/
    }
}