function calc (cWeight, cHours,cMinutes) {
 //calculate Calories Burnt
//convert lbs into kgs

cweight=cWeight/2.2;
var time_unit=eval(cHours) * 60 + eval(cMinutes); 
extype_cal=document.CalorieCalculator.extype.options[document.CalorieCalculator.extype.selectedIndex].value;
ccalories=time_unit * cweight * extype_cal
return ccalories;
}

function Reset()
{
document.CalorieCalculator.cWeight.value="";
document.CalorieCalculator.extype.selectedIndex=0;
document.CalorieCalculator.duration_hour.value="";
document.CalorieCalculator.duration_minutes.value="";
document.CalorieCalculator.cCalories.value="";
document.CalorieCalculator.cWeight.focus();
}

// Checks to see if the entered value is numeric
function isNum(passedVal) {
     if (passedVal == "") return false;

     for (i = 0; i < passedVal.length; i++) {
          if (passedVal.charAt(i) < "0") return false;
          if (passedVal.charAt(i) > "9") return false;
     }

     return true;
}

function process() {
if (!gIsNumber(document.CalorieCalculator.cWeight.value,1)) { 
   alert("You must enter a positive number for weight");
   document.CalorieCalculator.cWeight.focus();
   document.CalorieCalculator.cWeight.select();
   return false;
}

if (document.CalorieCalculator.extype.selectedIndex < 1)
{
   alert("You must select an exercise");
   document.CalorieCalculator.extype.focus();
   return false;
}
 var cHours=document.CalorieCalculator.duration_hour.value; 
 var cMinutes=document.CalorieCalculator.duration_minutes.value;

// check if fields are blank
if(cHours.charAt(0) == ' ' || cHours.charAt(0) == '' ) 
{
	cHours = "0";
	document.CalorieCalculator.duration_hour.value = "0";
}
else if(!isNum(cHours)) // is it numeric ?
{
	alert("Enter numeric value for hours");
	document.CalorieCalculator.duration_hour.focus();
	document.CalorieCalculator.duration_hour.select();
	return false;
}
if(cMinutes.charAt(0) == ' ' || cMinutes.charAt(0) == '' ) 
{
	cMinutes = "0";
	document.CalorieCalculator.duration_minutes.value = "0";
}
else if(!isNum(cMinutes)) // is it numeric ?
{
	alert("Enter numeric value for minutes");
	document.CalorieCalculator.duration_minutes.focus();
	document.CalorieCalculator.duration_minutes.select();
	return false;
}

 // check for bounds
 if(cHours < 0 || cHours > 99)
 {
  window.alert("You should enter a number between 0 and 99 inclusive for hours");
  document.CalorieCalculator.duration_hour.focus();
  document.CalorieCalculator.duration_hour.select();
  return false;
 }
 if(cMinutes < 0 || cMinutes > 60)
 {
   window.alert("You should enter a number between 0 and 60 inclusive for minutes");
   document.CalorieCalculator.duration_minutes.focus();
   document.CalorieCalculator.duration_minutes.select();
   return false;
 }

// calculate cals
 var CWeight=document.CalorieCalculator.cWeight.value; 
 result=calc(CWeight, cHours, cMinutes);
 document.CalorieCalculator.cCalories.value=Math.round(result);
}