<!--- Code to calculate Starting Age --->
function Calculate() {
	var m = parseInt(document.AgeCalc.Month.options[document.AgeCalc.Month.selectedIndex].value);
	var y = parseInt(document.AgeCalc.Year.options[document.AgeCalc.Year.selectedIndex].value);
	if (y != 0 && m != 0) {
		if (y < 1997 || m < 7) 
			document.AgeCalc.KStart.value = y + 4;
		else
			document.AgeCalc.KStart.value = y + 5;
			
		document.AgeCalc.PPStart.value = parseInt(document.AgeCalc.KStart.value) + 1;
		document.AgeCalc.Y1Start.value = parseInt(document.AgeCalc.KStart.value) + 2;
	}
}

<!--- Protect the starting year fields by moving focus to the month field --->
function MoveCursor() {
	document.AgeCalc.Month.focus(); 
}

<!--- Clear the Starting Year fields when a birth month or year is changed --->
function Clear() {
	document.AgeCalc.KStart.value = "";
	document.AgeCalc.PPStart.value = "";
	document.AgeCalc.Y1Start.value = "";
}


<!--- Form to enter Child's birth month and year and output school starting year --->
document.write("<form name='AgeCalc'>");

document.write("<table border='0'>");
document.write("<tr>");
document.write("	<td width='210'><b>Child's date of birth</b><br>(Enter Month, Year and click 'Go')</td>");
document.write("	<td>");
document.write("	<select name='Month' onChange = 'Clear()'>");
document.write("	   <option value=0>Select Month");
document.write("	   <option value=1>January");
document.write("	   <option value=2>February");
document.write("	   <option value=3>March");
document.write("	   <option value=4>April");
document.write("	   <option value=5>May");
document.write("	   <option value=6>June");
document.write("	   <option value=7>July");
document.write("	   <option value=8>August");
document.write("	   <option value=9>September");
document.write("	   <option value=10>October");
document.write("	   <option value=11>November");
document.write("	   <option value=12>December");
document.write("	</select>");
document.write("	<select name='Year' onChange = 'Clear()'>");
document.write("	   <option value=0>Select Year");
document.write("	   <option value=2000>2000");
document.write("	   <option value=2001>2001");
document.write("	   <option value=2002>2002");
document.write("	   <option value=2003>2003");
document.write("	   <option value=2004>2004");
document.write("	   <option value=2005>2005");
document.write("	   <option value=2006>2006");
document.write("	   <option value=2007>2007");
document.write("	   <option value=2008>2008");
document.write("	   <option value=2009>2009");
document.write("	</select>");
document.write("	</td>");
document.write("	<td>");
document.write("	<a href='JavaScript:Calculate()'><img src='images/Go.gif' border='0'></a>");
document.write("	</td>");
document.write("</tr>");
document.write("<tr>");
document.write("	<td>Child can start kindergarten in</td>");
document.write("	<td colspan='2'><input name='KStart' onFocus = 'MoveCursor()' size='10'></td>");
document.write("</tr>");
document.write("<tr>");
document.write("	<td>Child can start pre-primary in</td>");
document.write("	<td colspan='2'><input name='PPStart' onFocus = 'MoveCursor()' size='10'></td>");
document.write("</tr>");
document.write("<tr>");
document.write("	<td>Child can start Year One in</td>");
document.write("	<td colspan='2'><input name='Y1Start' onFocus = 'MoveCursor()' size='10'></td>");
document.write("</tr>");
document.write("</table>");

document.write("</form>");

