// common javascript script string functions

function keepChars(strValues, strSource)
{
	var a, x, y, z;
	var strOut = "";
	var keepChar;
	var nextChar;

	if (strValues.length == 0 || strSource.length == 0)
		return strSource;

	z = strValues.length
	y = strSource.length
	for (x=0; x < y; x++)
	{
		keepChar = "";
		nextChar = strSource.charAt(x);
		for (a=0; a < z; a++)
		{
			if (nextChar == strValues.charAt(a))
			{
				keepChar = nextChar;
				break;
			}
		}

		strOut += keepChar
	}

	return strOut
}

function limitFieldSize(field, maxsize)
{
	if (field.value.length > maxsize)
		field.value = field.value.substring(0, maxsize)
}

function limitFieldSizeEx(field, maxsize, statfield)
{
	if (field.value.length > maxsize)
		field.value = field.value.substring(0, maxsize)
	else
		statfield.value = maxsize - field.value.length
}


function trim(string)
{
	if (string.length == 0)
		return string

	return string.replace(/^\s*|\s*$/g,"");	
}

function encode(string) 
{
	// encode harmful characters in string that may trash listbox display
	var x = 0
	var newStr = ""

	if (string.length == 0)
		return newStr
		 
	for (x=0; x<string.length; x++) 
	{
		if (string.charAt(x) == "<")
			newStr += "%3C"
		else if (string.charAt(x) == ">")
			newStr += "%3E"
		else
			newStr += string.charAt(x)
	}

	return newStr
}