function change(a){
	switch(a){
	case 01:	
		var number = 01;
		break;
	case 02:
		var number = 02;
		break;
	case 03:
		var number = 03;
		break;
	case 04:
		var number = 04;
		break;
	case 05:
		var number = 05;
		break;
	case 06:
		var number = 06;
		break;
	case 07:
		var number = 07;
		break;
	case 88:
		var number = 88;
		break;
	case 99:
		var number = 99;
		break;
	case 10:
		var number = 10;
		break;
	case 11:
		var number = 11;
		break;
	case 12:
		var number = 12;
		break;
	case 13:
		var number = 13;
		break;
	case 14:
		var number = 14;
		break;		
	case 15:
		var number = 15;
		break;
	case 16:
		var number = 16;
		break;
	default:
		var number = 00;
	}
	var reg = /\?/;
		if(reg.exec(location.search)){
			var reg2 = /nav/;
			if(reg2.exec(location.search)){
				var new_url = location.href;
				location.href= new_url.replace(/nav=\d{1,2}/,"nav="+number);
			}
			else{
				location.href = location.href+"&nav="+number;
			}
		}
		else{
			location.href = location.href+"?nav="+number;
		}
}