function calculateAmount() {
    var totalAmount=0;

    for(var i=1;i<5;i++) {

		var weight ="weight"+i;
		var weightType ="weightType"+i;
		var amountType ="amountType"+i;
		
	if(document.getElementById(weight).value) {

		if(!isNaN(document.getElementById(weight).value)) {

			if(document.getElementById(weightType).value==0) {

				alert("Please select weight type");
				document.getElementById(weightType).focus();
				return false;
				break;

			}

			if(document.getElementById(amountType).value==0) {

				alert("Please select carat");
				document.getElementById(amountType).focus();
				return false;
				break;

			}
			
			var weightValue=(document.getElementById(weight).value);
			var weightTypeValue=(document.getElementById(weightType).value);
			var amountTypeValue=(document.getElementById(amountType).value);

			var totalAmount=eval(totalAmount+weightValue*amountTypeValue*weightTypeValue/10);



		}else{

			alert("Please enter weight in number format.");
			document.getElementById(weight).focus();
			return false;
			break;

		   }
		   if(isInteger(totalAmount)==false){
		   
		   document.getElementById("showAmount").innerHTML=totalAmount.toFixed(2);
		   
		   }else{
		   
		   document.getElementById("showAmount").innerHTML=totalAmount+".00";
		   
		   }
		
			

	 }
	
   }

 }
 
function isInteger(n) {
    return (typeof n == 'number' && /^-?\d+$/.test(n+''));

 }

function validateRightEnvelope() {

	if(document.getElementById('firstNameRight').value==0) {

		alert("Please enter first name");
		document.getElementById('firstNameRight').focus();
		return false;
	}
	
	if(document.getElementById('lastNameRight').value==0) {

		alert("Please enter last name");
		document.getElementById('lastNameRight').focus();
		return false;
	}

	if(document.getElementById('countryRight').value==0) {

		alert("Please select country");
		document.getElementById('countryRight').focus();
		return false;

	}

	if(document.getElementById('addressRight').value==0) {

		alert("Please enter address");
		document.getElementById('addressRight').focus();
		return false;
	}

	if(document.getElementById('termsConditionsRight').checked==false) {

		alert("Please accept terms and conditions.");
		document.getElementById('termsConditionsRight').focus();
		return false;

	}

}