// FINANCE CALC FORM
function validateCalculator() {
	var forminvalid = false;
	var formtext = "";
	formtext = 'Error! Please include the following details:\n\n';
	if (document.getElementById('financeCalc_Loan').value == "") {
		formtext = formtext + '  - Loan Amount\n';
		forminvalid = true;
	}
	if (document.getElementById('financeCalc_Rate').value == "") {
		formtext = formtext + '  - Rate\n';
		forminvalid = true;
	}
	if (document.getElementById('financeCalc_Term').value == "") {
		formtext = formtext + '  - Term\n';
		forminvalid = true;
	}
	if (forminvalid == true)
	{
		alert(formtext);
		return false;
	}
	else
	{
		showpay();
	}
}

// FINANCE CALCULATOR
function roundNumber(num, dec) {
	var result = Math.round(num*Math.pow(10,dec))/Math.pow(10,dec);
	return result;
}

function showpay() {
	 var loanAmount = document.getElementById('financeCalc_Loan').value
	 var loanDeposit = document.getElementById('financeCalc_Deposit').value
	 var loanTerm = document.getElementById('financeCalc_Term').value
	 var loanRate = document.getElementById('financeCalc_Rate').value / 1200;
	 //document.getElementById('calculateDiv').style.display='none';
	 //document.getElementById('monthlyPayment').style.display='block';
	 document.getElementById('monthlyPayment').innerHTML = "= $"+roundNumber((loanAmount - loanDeposit) * loanRate / (1 - (Math.pow(1/(1 + loanRate), loanTerm))),2)+" / month *";
}

function blockNonNumbers(obj, e, allowDecimal, allowNegative)
{
	var key;
	var isCtrl = false;
	var keychar;
	var reg;
		
	if(window.event) {
		key = e.keyCode;
		isCtrl = window.event.ctrlKey
	}
	else if(e.which) {
		key = e.which;
		isCtrl = e.ctrlKey;
	}
	
	if (isNaN(key)) return true;
	
	keychar = String.fromCharCode(key);
	
	// check for backspace or delete, or if Ctrl was pressed
	if (key == 8 || isCtrl)
	{
		return true;
	}

	reg = /\d/;
	var isFirstN = allowNegative ? keychar == '-' && obj.value.indexOf('-') == -1 : false;
	var isFirstD = allowDecimal ? keychar == '.' && obj.value.indexOf('.') == -1 : false;
	
	return isFirstN || isFirstD || reg.test(keychar);
}

function extractNumber(obj, decimalPlaces, allowNegative)
{
	var temp = obj.value;
	
	// avoid changing things if already formatted correctly
	var reg0Str = '[0-9]*';
	if (decimalPlaces > 0) {
		reg0Str += '\\.?[0-9]{0,' + decimalPlaces + '}';
	} else if (decimalPlaces < 0) {
		reg0Str += '\\.?[0-9]*';
	}
	reg0Str = allowNegative ? '^-?' + reg0Str : '^' + reg0Str;
	reg0Str = reg0Str + '$';
	var reg0 = new RegExp(reg0Str);
	if (reg0.test(temp)) return true;

	// first replace all non numbers
	var reg1Str = '[^0-9' + (decimalPlaces != 0 ? '.' : '') + (allowNegative ? '-' : '') + ']';
	var reg1 = new RegExp(reg1Str, 'g');
	temp = temp.replace(reg1, '');

	if (allowNegative) {
		// replace extra negative
		var hasNegative = temp.length > 0 && temp.charAt(0) == '-';
		var reg2 = /-/g;
		temp = temp.replace(reg2, '');
		if (hasNegative) temp = '-' + temp;
	}
	
	if (decimalPlaces != 0) {
		var reg3 = /\./g;
		var reg3Array = reg3.exec(temp);
		if (reg3Array != null) {
			// keep only first occurrence of .
			//  and the number of places specified by decimalPlaces or the entire string if decimalPlaces < 0
			var reg3Right = temp.substring(reg3Array.index + reg3Array[0].length);
			reg3Right = reg3Right.replace(reg3, '');
			reg3Right = decimalPlaces > 0 ? reg3Right.substring(0, decimalPlaces) : reg3Right;
			temp = temp.substring(0,reg3Array.index) + '.' + reg3Right;
		}
	}
	
	obj.value = temp;
}