function calculate (number) {

this.number = number;

var amountobjectpath = "document.frmPower.txtamount"+number+".value";
var quantityobjectpath = "document.frmPower.txtquantity"+number+".value";
var powerobjectpath = "document.frmPower.txtpower"+number+".value";
var kwtotalobjectpath = "document.frmPower.totalkw"+number+".value";

var amount = eval(amountobjectpath);
var quantity = eval(quantityobjectpath);
var power = eval(powerobjectpath);

var kwtotal;


if (quantity != 0 && power != 0) {

	kwtotal = quantity * power;

} else {

	if (quantity != 0) {
	
	kwtotal = quantity * amount;
	
	} 

}

if (power != 0 && quantity == 0 || quantity == "" || quantity == 0) {

	if (quantity == 0) {
	quantity = "";
	}
	
	kwtotal = 0;
}

var displaykwtotal = "document.frmPower.totalkw"+number+".value = '"+kwtotal+"';";
eval(displaykwtotal);

calctotal(189);

}

function calctotal(myvalue) {
var finalvalue = 0;
for (i=1;i<myvalue;i++){
	var mydocument = "document.frmPower.totalkw"+i+".value";
	
	if (eval(mydocument) != 0 || eval(mydocument) != "") {
	finalvalue = parseInt(finalvalue) + parseInt(eval(mydocument));  
	}
}
//thefinalvalue = finalvalue / 1000;
thefinalvalue = finalvalue;
document.frmPower.totalamount.value = thefinalvalue;
}

function onequantity(number) {	
this.number = number;

var checkobjectpath = "document.frmPower.txtcheck"+number+".value";	
var checkobjectpathchecked = "document.frmPower.txtcheck"+number+".checked";	

var checkvalue = eval(checkobjectpath);
var checkchecked = eval(checkobjectpathchecked);

if (checkvalue == number) {
	if (checkchecked == true) {
		var setquantity = "document.frmPower.txtquantity"+number+".value = 1;";
		eval(setquantity);
		calculate (number);
	}
	else {
		var setquantity = "document.frmPower.txtquantity"+number+".value = '';";
		eval(setquantity);
		calculate (number);
	}
}

}

function finalcheck() {
if (document.frmPower.totalamount.value == "")
        {
            alert ("The page cannot be submitted as there is no total amount.");
            return false;
        }       // end if
if (document.frmPower.totalamount.value == 0)
        {
            alert ("The page cannot be submitted as the total amount needs to be greater than 0.");
            return false;
        }       // end if
}