var minYear=1600;
var maxYear=2025;
function isInteger(s){
	var i;
	for (i = 0; i < s.length; i++){   
		// Check that current character is number.
		var c = s.charAt(i);
		if (((c < "0") || (c > "9"))) return false;
	}
	// All characters are numbers.
	return true;
}

function isYear(dtStr){
	var strYear=dtStr;
	if (isInteger(dtStr)==false){
		return false;
	}	
	if (strYear < minYear || strYear > maxYear){
		return false;
	}

return true
}

function ValidateForm(){
	var date1=document.searchForm.fromYear;
	var date2=document.searchForm.toYear;
	if (date1.value != ''){
		if (isYear(date1.value)==false){
			alert('The From Year, if entered, must be a valid year (XXXX) between 1600 and 2025.'); 
			date1.focus();
			return false;
		}
	}
	if (date2.value != ''){
		if (isYear(date2.value)==false){
			alert('The To Year, if entered, must be a valid year (XXXX) between 1600 and 2025.'); 
			date2.focus()
			return false;
		}
	}
	if(date1.value != '' && date2.value != ''){
		if (date1.value > date2.value){
			alert('From date should be less than To date.  They will be switched as the form is submitted.');
			temp = date1.value;
			date1.value = date2.value;
			date2.value = temp;
		}
	}
	document.searchForm.action = '/historianscorner/index.cfm?key=' + document.searchForm.keyword.value + '&action=searchResult';
	return true;
 }