js 计算两个时间之间间隔多少小时

		var dt1 = "2009-11-5 10:30"  
			    var dt2 = "2009-11-8 9:20"
			    function getHoursDiff(dt1,dt2) {
    
    
			        if(typeof(dt1)=="string") {
    
    
			            dt1=new Date(dt1.replace(/-/,'/'));
			            dt2=new Date(dt2.replace(/-/,'/'));
			        }
			        var res=dt2-dt1;
			        if(isNaN(res))
			            throw Error("invalid dates arguments");
			        return res/(1000*60*60);
			    }
			    var re=getHoursDiff(dt1,dt2);
			    var h=parseInt(re);
			    var m=parseInt((re-h)*60);
			    alert("时间相隔"+h+"小时"+m+"分钟");