function showRepayment(){
	var loan_amount = document.getElementById('loan_amount').value;
 if(isNaN(loan_amount)){
		alert('The loan amount should be a number');
		return false;
	}
	var loan_interest = (document.getElementById('loan_interest').value / 100 / 12);
 if(isNaN(loan_interest)){
		alert('The loan interest should be a number');
		return false;
	}
	var loan_period = document.getElementById('loan_period').value;
 if(isNaN(loan_period)){
		alert('The loan period should be a number');
		return false;
	}

	//P = principle amount; i = interest rate; n = years of loan

	var loan_repayment = (loan_interest * loan_amount) / (1 - Math.pow((1 + loan_interest), ((loan_period * 12) * -1)));

	document.getElementById('loan_repayment').value = parseFloat(parseInt(loan_repayment * 100) / 100);

	var loan_interest_only = (loan_amount * loan_interest);

	document.getElementById('loan_interest_only').value = parseFloat(parseInt(loan_interest_only * 100) / 100);

	/*

	(this.P * (loan_period / 12)) /
	            (1 - Math.pow(1 + (this.i / 12), (this.n * -1))),
	            'payment'

(this.P * this.i) / 12



*/

}