function opacity(id, opacStart, opacEnd, millisec) { 
    //speed for each frame 
    var speed = Math.round(millisec / 100); 
    var timer = 0; 
    var to
    //determine the direction for the blending, if start and end are the same nothing happens 
    if(opacStart > opacEnd) { 
		for(i = opacStart; i >= opacEnd; i--) { 
		to = setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed)); 
		timer++; 
		}
		clearTimeout(to); 
    } 
    else if(opacStart < opacEnd) {
    		for(i = opacStart; i <= opacEnd; i++) { 
				to = setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed)); 
				timer++; 
				} 
				clearTimeout(to);
	} 
} 

//change the opacity for different browsers 
function changeOpac(opacity, id) { 
	if (document.getElementById(id)){
    var object = document.getElementById(id).style; 
    object.opacity = (opacity / 100); 
    object.MozOpacity = (opacity / 100); 
    object.KhtmlOpacity = (opacity / 100); 
    object.filter = "alpha(opacity=" + opacity + ")";
    } 
}