function flip_img(id,img){
	var agent=navigator.userAgent.toLowerCase();
	
	this.mac = (agent.indexOf("mac")!=-1); 
	if (this.mac && (agent.indexOf("msie 5.")!=-1)){
		//alert(agent);
	
		document.getElementById(id).src = img;
		
	}else{

		document.getElementById(id).src = img;
	}
}