// checks all the relevant form fields have been entered.
function step1validate() {
	
	var year = document.getElementById("AppDOBYear").value
	
	if (document.getElementById("AppName").value == "") {
		alert("Please enter your full name");
		document.getElementById("AppName").focus();
	} else if (document.getElementById("AppAddress1").value == "") {
		alert("Please enter the first line of your postal address");
		document.getElementById("AppAddress1").focus();
	} else if (document.getElementById("AppPostcode").value == "") {
		alert("Please enter your postcode");
		document.getElementById("AppPostcode").focus();
	//do check to ensure date year is a 4 digit integer	
	} else if (isNaN(parseInt(year.charAt(0))) || isNaN(parseInt(year.charAt(1))) || isNaN(parseInt(year.charAt(2))) || isNaN(parseInt(year.charAt(3)))) {
		alert("Please enter a valid year of birth (4 digits)");
		document.getElementById("AppDOBYear").focus();
	} else {
		//do check to ensure applicant is over 18 years old	
		var dtDOB = new Date(year, document.getElementById("AppDOBMonth").value - 1, document.getElementById("AppDOBDay").value);
		var dtNow = new Date();
		var timeDOB = dtDOB.getTime();
		var timeNow = dtNow.getTime();
		var timeDiff = timeNow - timeDOB;
		var yearDiff = timeDiff / (1000 * 60 * 60 * 24 * 365.25);
		if (yearDiff < 18) {
			alert("You must be aged 18 or over to apply for this position");
			document.getElementById("AppDOBYear").focus();
		} else {
			document.getElementById("step1form").submit();
		}
	}
}

function step3validate() {

	//do checks to ensure date years are 4 digit integers
		
	var year1 = document.getElementById("AppRef1FromDateYear").value;
	var year2 = document.getElementById("AppRef1ToDateYear").value;
	var year3 = document.getElementById("AppRef2FromDateYear").value;
	var year4 = document.getElementById("AppRef2ToDateYear").value;

	if (isNaN(parseInt(year1.charAt(0))) || isNaN(parseInt(year1.charAt(1))) || isNaN(parseInt(year1.charAt(2))) || isNaN(parseInt(year1.charAt(3)))) {
		alert("Please enter a valid year (4 digits)");
		document.getElementById("AppRef1FromDateYear").focus();
	} else if (isNaN(parseInt(year2.charAt(0))) || isNaN(parseInt(year2.charAt(1))) || isNaN(parseInt(year2.charAt(2))) || isNaN(parseInt(year2.charAt(3)))) {
		alert("Please enter a valid year (4 digits)");
		document.getElementById("AppRef1ToDateYear").focus();
	} else if (isNaN(parseInt(year3.charAt(0))) || isNaN(parseInt(year3.charAt(1))) || isNaN(parseInt(year3.charAt(2))) || isNaN(parseInt(year3.charAt(3)))) {
		alert("Please enter a valid year (4 digits)");
		document.getElementById("AppRef2FromDateYear").focus();
	} else if (isNaN(parseInt(year4.charAt(0))) || isNaN(parseInt(year4.charAt(1))) || isNaN(parseInt(year4.charAt(2))) || isNaN(parseInt(year4.charAt(3)))) {
		alert("Please enter a valid year (4 digits)");
		document.getElementById("AppRef2ToDateYear").focus();
	} else {
		document.getElementById("step3form").submit();
	}
}

function step6validate() {
	if(!(document.getElementById("AppReadHours").checked && document.getElementById("AppReadPressure").checked && document.getElementById("AppReadTravel").checked && document.getElementById("AppReadSmoking").checked && document.getElementById("AppReadTransport").checked)) {
		alert("Please ensure you have ticked all of the boxes to indicate that you have read and understood all of the corresponding statements");
		return false;
	} 
	return true;
}