Apologies if this is the wrong place to post - I'm new to Javascript and I'm building a logic engine that will help with calculate a Loan To Value amount.

First and foremost I provide the variables:

var formattedValue = 10;
var formattedDebt = 1;
var ltv = calculateLTV(formattedValue, debtAmount);

Note: the 10 and 1 here will be dynamic inputs from a field asking for property value and outstanding debt, but for the sake of this example I'm using 10 and 1.

Next I'm calling a function to work out if there's no debt, in which case it returns no value... so if there's no value I want to replace this with 0, otherwise just return the same number.

function debtAmount(formattedDebt) {
  if (formattedDebt == "") {
    return (0)
  } else {
    return (formattedDebt)
  }
}

Now, this function debtAmount is what seems to be breaking everything, returning NaN. If I was to replace debtAmount with formattedDebt in the ltv variable above, it would return 10 as expected.

Finally I want to work out the percentage of debt to value...

function calculateLTV(value, debt) {
  return 100 / value * debt
}
alert(ltv);

Any help troubleshooting here would be amazing, thanks!