// script to verify a form submission


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

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

// Check whether string s is empty.
function isEmpty(s)
{ return ((s == null) || (s.length == 0)) }

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

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;
}

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

function ForceEntry(objField, FieldName)
{
		var strField = new String(objField.value);
		if (isWhitespace(strField)) {
			alert("Please fill in " + FieldName);
			objField.focus();
			objField.select();
			return false;
		}

		return true;
}

function isEmail (objField, FieldName)
{
	
    var s = new String(objField.value);
	
    if (isEmpty(s)) return true;
   
    if (isWhitespace(s)) return true;    

    // 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) != "@")) {
		alert("Please enter a valid " + FieldName);
		objField.focus();
		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) != ".")) {
		alert("Please enter a valid " + FieldName);
		objField.focus();
		return false;
	}		
    else return true;
}