function isDigit(c)
{
	var retVal = false;
	if ((c >= '0') && (c <= '9'))
	retVal = true;
	return retVal;
}//isDigit(c)

function isChar(c)
{
	var retVal = false;
	if ((c >= 'a') && (c <= 'z'))
	retVal = true;
	if ((c >= 'A') && (c <= 'Z'))
	retVal = true;
	return retVal;
}//isChar(c)

function isNumber(s)
{
	var retVal = false;
	for (var i = 0; i < s.length; i++)
	if (isDigit(s.charAt(i)))
	retVal = true;
	else
	{
	retVal = false;
	break;
	}
	return retVal;
}//isNumber(s)

function isValidPhoneNumber(ph_num) 
{
	var inLen = ph_num.length;
	
	alert("inLen = " + inLen)
	
	var i, ch;
	var errmsg="";
	
	for(i=0; i<inLen; i++) 
	{
		retVal = false;
		ch=ph_num.substring(i,i+1);
		if (isDigit(ch) || (ch=='-') || (isChar(ch)) || (ch==' ')) 
			{}
		else 
			return false;
	} // for
	return true;
} // isValidPhoneNumber