function calc_dripRate( form )
{
	emitterFlowUnits = parseFloat( form.emitterFlowUnits.value);
	spacingUnits = parseFloat( form.spacingUnits.value);
	distanceUnits = parseFloat( form.distanceUnits.value);
	appRateUnits = parseFloat( form.appRateUnits.value);

	emitterFlow = parseFloat( form.emitterFlow.value) * emitterFlowUnits;
	spacing = parseFloat( form.spacing.value) * spacingUnits;
	distance = parseFloat( form.distance.value) * distanceUnits;
	
	appRate = spacing / 2.54;
	appRate = appRate * ( distance / 2.54 );
	appRate =  ( 231 * emitterFlow * 60 ) / appRate;
	appRate = parseFloat( appRate );
	appRate = appRate * appRateUnits;
	appRate = Math.round( appRate * 10000 );
	appRate = appRate / 10000;

	form.appRate.value = appRate;								
}