不如这样:
function CountTotal(){
var rtotal = 0.0;
var room = document.getElementsByTagName("INPUT");
for(var i=0;i<room.length;i++){
if( room[i].type == "text" && room[i].name.indexOf("rtotal") != -1 )
            rtotal += parseInt(room[i].value,10);
}
                   alert(rtotal);
}