// clear the boxes
        function clearBoxes(form)
                {
                form.powertot.value = "";              // clear the box(s)
                form.powerroll.value = "";
                form.powerair.value = "";
                form.powerhill.value = "";
                form.powercrank.value = "";
                form.input_length.value = "";
                form.input_height.value = "";
                form.input_time.value = "";
                form.input_weight.value = "";
				return false;
            }

  
//  Calculate Power etc...

    function solve(form)
            {
    var Eff     =  0.98;    
    var cr       =  0.005;
    var cwa   =  0.4;
    var Wt     = form.input_weight.value;
    var time    = form.input_time.value;    
    var height  = form.input_height.value;
    var length    = form.input_length.value;


    var V        = length/time;
    var powerair = cwa * 0.5 * 1.225 * V*V*V;
    var powerroll =cr * Wt * 9.81 * V ;
    var powerhill = Wt * 9.81 * height / time ;
    var powertot = powerair + powerroll + powerhill;
    var powercrank = powertot / Eff ;

 
    powerair = Math.round(powerair*10)/10+' watt';
    powerhill = Math.round(powerhill*10)/10+' watt';
    powerroll = Math.round(powerroll*10)/10+' watt';
    powercrank = Math.round(powercrank*10)/10+' watt';
    powertot = Math.round(powertot*10)/10+' watt';

    form.powertot.value = powertot ;
    form.powerair.value = powerair ;
    form.powerhill.value = powerhill ;
    form.powerroll.value = powerroll ;
    form.powercrank.value = powercrank ;
	return false;
      }