function trim(str)
{
	var arrStr = new Array();
	var lenStr;
	var rtnStr = "";
	
	if(str == null)
		return "";

	lenStr = str.length;
	for (var i = 0; i <lenStr; i++)
	{
		arrStr[i] = str.charAt(i);
	
		if (arrStr[i] == " ")
		{
			if (i > 0)
			{
				if (!arrStr[i - 1])
					arrStr[i] = "";
			}
			else
				arrStr[i] = "";
		}
	}
	
	for (i = lenStr - 1; i >= 0; i--)
	{
		if (arrStr[i] == " ")
		{
			if (i < lenStr - 1)
			{
				if (!arrStr[i + 1])
					arrStr[i] = "";
			}
			else
				arrStr[i] = "";
		}
	}
	
	for (i = 0; i < lenStr; i++)
		if (arrStr[i])
			rtnStr += arrStr[i];
	
	return rtnStr;
}