// whitespace characters
var whitespace = " \t\n\r";

// Returns true if string s is empty or 
// whitespace characters only.

function isWhitespace (s)

{   var i;

    // Is s empty?
    if (isEmpty(s)) return true;

    // Search through string's characters one by one
    // until we find a non-whitespace character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
	// Check that current character isn't whitespace.
	var c = s.charAt(i);

	if (whitespace.indexOf(c) == -1) return false;
    }

    // All characters are whitespace.
    return true;
}
/****************************************************************/
// Check whether string s is empty.

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

function replaceAll (s, fromStr, toStr)
{
	var new_s = s;
	for (i = 0; i < 100 && new_s.indexOf (fromStr) != -1; i++)
	{
		new_s = new_s.replace (fromStr, toStr);
	}
	return new_s;
}

/****************************************************************/

/* PURPOSE:  Since we are using the single tick mark as the
	string delimiter to construct our SQL queries, a string with
	a tick mark in it will cause a SQL error.  Therefore we replace
	all "'" with "''", which eliminates the possibility of a SQL error.
*/

function sqlSafe (s)
{
	var new_s = s;
	new_s = replaceAll (new_s, "'", "|");
	new_s = replaceAll (new_s, "|", "''");
	new_s = replaceAll (new_s, "\"", "|");
	new_s = replaceAll (new_s, "|", "''");
	return new_s;
}

// isEmail (STRING s [, BOOLEAN emptyOK])
// 
// Email address must be of form a@b.c ... in other words:
// * there must be at least one character before the @
// * there must be at least one character before and after the .
// * the characters @ and . are both required
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isEmail(strEmail){
	if (window.RegExp) {	
		var re = new RegExp('^[A-Z0-9_-]{1}[A-Z0-9_\.-]*[@]{1}[A-Z0-9_-]+[\.]{1}[A-Z0-9_-]+[A-Z0-9_\.-]+$', 'i');
		return strEmail.match(re) 
		//return re.test(strEmail);
	}
	else {
		return isEmailNoRegex(strEmail)
	}
}

function isEmailNoRegex(s)
{   if (isEmpty(s)) 
       if (isEmailNoRegex.arguments.length == 1) return defaultEmptyOK;
       else return (isEmailNoRegex.arguments[1] == true);
   
    // is s whitespace?
    if (isWhitespace(s)) return false;
    
    // 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;

    // 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;
}