Strange Javascript Behavior

[rockinthesix]

I am trying to write a CustomValidator for ASP.NET and am getting strange behavior with my javascript.

This WORKS:

		var myString = "2006-07";

		var mySplitResult = myString.split("-");
		var firstyear = mySplitResult[0];
		var firstdecade = Right(firstyear,2);
		var secondyear = mySplitResult[1];
		document.write("The Year Spread is " + myString);
		document.write("<br /><br />The first year is [" + firstyear + "]");
		document.write("<br />The first decade is [" + firstdecade + "]");
		document.write("<br />The second year is  [" + secondyear + "]");
		document.write("<br /><br />[first decade] + 1 = second year: " + (parseInt(firstdecade) + 1 == parseInt(secondyear)))

		function Left(str, n) {
			if (n <= 0)
				return "";
			else if (n > String(str).length)
				return str;
			else
				return String(str).substring(0, n);
		}
		function Right(str, n) {
			if (n <= 0)
				return "";
			else if (n > String(str).length)
				return str;
			else {
				var iLen = String(str).length;
				return String(str).substring(iLen, iLen - n);
			}
		}

This DOES NOT

		var myString = "2007-08";

		var mySplitResult = myString.split("-");
		var firstyear = mySplitResult[0];
		var firstdecade = Right(firstyear,2);
		var secondyear = mySplitResult[1];
		document.write("The Year Spread is " + myString);
		document.write("<br /><br />The first year is [" + firstyear + "]");
		document.write("<br />The first decade is [" + firstdecade + "]");
		document.write("<br />The second year is  [" + secondyear + "]");
		document.write("<br /><br />[first decade] + 1 = second year: " + (parseInt(firstdecade) + 1 == parseInt(secondyear)))

		function Left(str, n) {
			if (n <= 0)
				return "";
			else if (n > String(str).length)
				return str;
			else
				return String(str).substring(0, n);
		}
		function Right(str, n) {
			if (n <= 0)
				return "";
			else if (n > String(str).length)
				return str;
			else {
				var iLen = String(str).length;
				return String(str).substring(iLen, iLen - n);
			}
		}

Why would 06+1=07 return TRUE
and 07+1=08 return FALSE

[rockinthesix]

Also, this is ultimately what my function should look like... the above is a simplified version for readability.

//          Custom JavaScripts to enhance the user experience


//<![CDATA[
//FiscalYear Custom Control Client Side Validation
function FiscalYear_ClientValidate(sender, args) {
    var textboxValue = args.Value;

    if (textboxValue.match(/^((1[8-9]|[2-3]\d)\d{2})$/))
        args.IsValid = true
    else if (textboxValue.match(/^((\d)(\d)(\d)(\d)-(\d)(\d))$/)) {
        var SplitYears = textboxValue.split("-");
        var FirstYear = SplitYears[0];
        var FirstYear_Decade = Right(FirstYear, 2);
        var LastYear = SplitYears[1];


        if (parseInt(FirstYear_Decade) + 1 == parseInt(LastYear)) {
            args.IsValid = true;
        }
        else if (parseInt(FirstYear_Decade) - 99 == parseInt(LastYear)) {
            args.IsValid = true;
        }
        else
            args.IsValid = false;
    }
    else
        args.IsValid = false;
    return;
}
//End FiscalYear Custom Control Client Side Validation
function Left(str, n) {
    if (n <= 0)
        return "";
    else if (n > String(str).length)
        return str;
    else
        return String(str).substring(0, n);
}
function Right(str, n) {
    if (n <= 0)
        return "";
    else if (n > String(str).length)
        return str;
    else {
        var iLen = String(str).length;
        return String(str).substring(iLen, iLen - n);
    }
}

//]]>

[rockinthesix]

Ok, so it turns out that parseInt didn't work but parseFloat did... not entirely sure why that is.