// calculate the ASCII code of the given character
function CalcKeyCode(aChar) {
	var character = aChar.substring(0,1);
	var code = aChar.charCodeAt(0);
	return code;
}

function checkNumber(val) {
	var strPass = val.value;
	var strLength = strPass.length;
	var lchar = val.value.charAt((strLength) - 1);
	var cCode = CalcKeyCode(lchar);

	/* Check if the keyed in character is a number
	do you want alphabetic UPPERCASE only ?
	or lower case only just check their respective
	codes and replace the 48 and 57 */

	if (cCode < 48 || cCode > 57 ) {
		var myNumber = val.value.substring(0, (strLength) - 1);
		val.value = myNumber;
	}
	return false;
}

function IsNumeric(strString) //  check for valid numeric strings
{
	var strValidChars = "0123456789.-";
	var strChar;
	var blnResult = true;

	if (strString.length == 0) return false;

	//  test strString consists of valid characters listed above
	for (i = 0; i < strString.length; i++)
	{
		strChar = strString.charAt(i);
		if (strValidChars.indexOf(strChar) == -1)
		{
			blnResult = false;
			break;
		}
	}
	return blnResult;
}

function isEmpty (s)
{
	return ((s == null) || (s.length == 0))
}

function isDigit (c)
{
	return ((c >= "0") && (c <= "9"))
}


function isPositiveInteger (strString)
{
	if (isEmpty(strString))
	{
		return false;
	}
	if (strString == 0)
	{
		return false;
	}
	var i;
	for (i = 0; i < strString.length; i++)
    {
    	var c = strString.charAt(i);

     	if (!isDigit(c))
     		return false;
    }
    return true;
}

function trimInt(nr)
{
	for (var i = nr.length - 1; i >= 0; --i)
	{
		if ('0123456789'.indexOf(nr.charAt(i)) < 0)
		{
			nr = nr.substr(0, i) + '' + nr.substr(i + 1);
		}
	}
	return nr;
}

function IsInteger (strString)
{
	for (i = 0; i < strString.length; i++)
    {
    	var c = strString.charAt(i);

     	if (!isDigit(c))
     		return false;
    }
    return true;
}