function cal_pace(d,h,m,s){
var distance = d;
var hours = h;
var minutes = m;
var seconds = s;
if(distance.length > 0 && hours.length > 0 && minutes.length > 0 && seconds.length > 0)
{
var speed = parseFloat(hours) * 60.0 + parseFloat(minutes) + parseFloat(seconds) / 60.0;
speed = speed / parseFloat(distance);
var speed_minutes = Math.floor(speed);
var speed_seconds = Math.floor((speed - speed_minutes) * 60.0);
return (speed_minutes + '\'' + speed_seconds + '\"').toString();
}
return '0\'0\"';
}