// common JavaScript functions

/* ---------------- Common basic type operations/ --------------- */
// serial of functions to trim string
var whitespace = " \t\n\r";

function charInString (c, s)
{   for (i = 0; i < s.length; i++)
	{   if (s.charAt(i) == c) return true;
	}
	return false
}

function stripInitialWhitespace (s)
{   var i = 0;

	while ((i < s.length) && charInString (s.charAt(i), whitespace))
	   i++;

	return s.substring (i, s.length);
}

function stripEndingWhitespace (s)
{   var i = s.length - 1;

	while ((i > 0) && charInString (s.charAt(i), whitespace))
	   i--;

	return s.substring (0, i+1);
}

function trimString (s)
{
	return stripEndingWhitespace ( stripInitialWhitespace (s) );

}

// function to check E-mail address like string
function isEmail (s)
{
	// there must be >= 1 character before @, so we
	// start looking at character position 1
	// (i.e. second character)
	var i = 1;
	var sLength = s.length;

	if ( sLength <= 1 ) return false ;

	// look for @
	while ((i < sLength) && (s.charAt(i) != "@"))
	{ i++
	}

	if ((i >= sLength) || (s.charAt(i) != "@")) return false;
	else i += 2;

	// look for .
	while ((i < sLength) && (s.charAt(i) != "."))
	{ i++
	}

	// there must be at least one character after the .
	if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
	else return true;
}

// function to check IP Address like string
function isIPAddress ( strIPAddress )
{
	regExp = new RegExp ( "([0-9]{1,3})[\.]{1,}([0-9]{1,3})[\.]{1,}([0-9]{1,3})[\.]{1,}([0-9]{1,3})" ) ;
	aParts = regExp.exec ( strIPAddress ) ;
	if ( aParts == null )
	{
		return false ;
	}

	if ( aParts.length != 5 )
	{
		return false ;
	}

	for ( nLoopCnt = 1 ; nLoopCnt < 5 ; nLoopCnt ++ )
	{
		if ( aParts [ nLoopCnt ] < 0 || aParts [ nLoopCnt ] > 255 )
		{
			return false ;
		}
	}

	return true ;
}

// function to check login name like string
function fn_CheckLoginName ( strLogin )
{
	strLogin = trimString( strLogin ) ;

	var checkOK = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-._";
	var checkStr = strLogin ;
	var allValid = true;
	for (i = 0;  i < checkStr.length;  i++)
	{
		ch = checkStr.charAt(i);
		for (j = 0;  j < checkOK.length;  j++)
		  if (ch == checkOK.charAt(j))
			break;
		if (j == checkOK.length)
		{
		  allValid = false;
		  break;
		}
	}
	if ( ! allValid )
	{
		return (false);
	}

	if ( checkStr.charAt(0) == '-' || checkStr.charAt(0) == '.' || checkStr.charAt(0) == '_' )
	{
		return (false);
	}

	return (true);
}

// function to check Domain name like string
function fn_CheckDomainName ( strDomainName )
{
	strDomainName = trimString ( strDomainName ) ;

	var checkOK = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-.";
	var checkStr = strDomainName;
	var allValid = true;
	for (i = 0;  i < checkStr.length;  i++)
	{
		ch = checkStr.charAt(i);
		for (j = 0;  j < checkOK.length;  j++)
		  if (ch == checkOK.charAt(j))
			break;
		if (j == checkOK.length)
		{
		  allValid = false;
		  break;
		}
	}
	if (!allValid)
	{
		return (false);
	}

	if ( checkStr.charAt(0) == '-' || checkStr.charAt(0) == '.' )
	{
		return (false);
	}

	return (true);
}
// function to check SECOND-Domain name like string
function fn_CheckSDomainName ( strDomainName )
{
	strDomainName = trimString ( strDomainName ) ;

	var checkOK = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-";
	var checkStr = strDomainName;
	var allValid = true;
	for (i = 0;  i < checkStr.length;  i++)
	{
		ch = checkStr.charAt(i);
		for (j = 0;  j < checkOK.length;  j++)
		  if (ch == checkOK.charAt(j))
			break;
		if (j == checkOK.length)
		{
		  allValid = false;
		  break;
		}
	}
	if (!allValid)
	{
		return (false);
	}

	if ( checkStr.charAt(0) == '-' || checkStr.charAt(0) == '.' )
	{
		return (false);
	}

	return (true);
}

// function to check year, month, day numbers
function fn_ValidateDate ( nYear , nMonth , nDay )
{
	if ( nMonth < 1 || nMonth > 12 ) return false ;
	if ( nDay < 1 || nDay > 31 ) return false ;
	if ( nMonth == 4 || nMonth == 6 || nMonth == 9 || nMonth == 11 )
	{
		if ( nDay > 30 ) return false ;
	}
	if ( nMonth == 2 )
	{
		if ( nYear % 4 == 0 )
		{
			if ( nYear % 100 == 0 )
			{
				if ( nYear % 400 == 0 )
				{
					if ( nDay > 29 ) return false ;
				}
				else
				{
					 if ( nDay > 28 ) return false ;
				}
			}
			else
			{
				if ( nDay > 29 ) return false ;
			}
		}
		else
		{
			if ( nDay > 28 ) return false ;
		}
	}

	return true ;
}

/* ---------------- /Common basic type operations --------------- */