function prefcheck(form){
	
	var Email = form.Email.value;  
	var Pref = form.Type.value;

msg = "";
msg_beg = "Please enter valid values for the following required fields:";

if ((Email == null) || (Email.length == 0)){
	msg += "\n\tEmail Address";
}else{
	if (!isEmail(Email)){
		msg += "\n\tValid Email Address must be of the form a@b.c";
		form.Email.focus();
		form.Email.select();
	}
}


if  (Pref == "XX"){
		msg += "\n\tNew newsletter format";
	}


if (msg != ""){
		alert(msg_beg + msg)
		return false
	}
	return true
}



// 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
//
function isEmail (s){

	if (isEmpty(s)) return false;
   
    // 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;
}

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

// isInteger (STRING s [, BOOLEAN emptyOK])
// 
// Returns true if all characters in string s are numbers.
//
// Accepts non-signed integers only. Does not accept floating 
// point, exponential notation, etc.
//
// We don't use parseInt because that would accept a string
// with trailing non-numeric characters.
//
// By default, returns defaultEmptyOK if s is empty.
// There is an optional second argument called emptyOK.
// emptyOK is used to override for a single function call
//      the default behavior which is specified globally by
//      defaultEmptyOK.
// If emptyOK is false (or any value other than true), 
//      the function will return false if s is empty.
// If emptyOK is true, the function will return true if s is empty.
//
// EXAMPLE FUNCTION CALL:     RESULT:
// isInteger ("5")            true 
// isInteger ("")             defaultEmptyOK
// isInteger ("-5")           false
// isInteger ("", true)       true
// isInteger ("", false)      false
// isInteger ("5", false)     true

function isInteger (s)

{   var i;

    if (isEmpty(s)) return false;

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

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is number.
        var c = s.charAt(i);
        if (!isDigit(c)) return false;
    }

    // All characters are numbers.
    return true;
}

// Returns true if character c is a digit 
// (0 .. 9).
function isDigit (c)
{   return ((c >= "0") && (c <= "9"))
}