function opacity(id, opacStart, opacEnd, millisec) {
	    //speed for each frame
	    var speed = Math.round(millisec / 100);
	    var timer = 0;
	
	    //determine the direction for the blending, if start and end are the same nothing happens
	    if(opacStart > opacEnd) {
	        for(i = opacStart; i >= opacEnd; i--) {
	            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
	            timer++;
	        }
	    } else if(opacStart < opacEnd) {
	        for(i = opacStart; i <= opacEnd; i++)
	            {
	            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
	            timer++;
	        }
	    }
	}
	
	//change the opacity for different browsers
	function changeOpac(opacity, id) {
	    var object = document.getElementById(id).style;
	    object.opacity = (opacity / 100);
	    object.MozOpacity = (opacity / 100);
	    object.KhtmlOpacity = (opacity / 100);
	    object.filter = "alpha(opacity=" + opacity + ")";
	}