// Email Field Validation

function stringEmpty (document.eventsignup.Email) {
    // CHECK THAT THE STRING IS NOT EMPTY
    if ( document.eventsignup.Email.length < 1 ) {
        return ( true );
    } else {
        return ( false );
    }
}

function noAtSign (document.eventsignup.Email) {
    // CHECK THAT THERE IS AN '@' CHARACTER IN THE STRING
    if (document.eventsignup.Email.indexOf ('@', 0) == -1) {
        return ( true );
    } else {
        return ( false );
    }
}

function nothingBeforeAt (document.eventsignup.Email) {
    // CHECK THERE IS AT LEAST ONE CHARACTER BEFORE THE '@' CHARACTER
    if ( document.eventsignup.Email.indexOf ( '@', 0 ) < 1 ) {
        return ( true );
    } else {
        return ( false );
    }
}

function noLeftBracket (document.eventsignup.Email) {
    // IF EMAIL ADDRESS IN FORM 'user@[255,255,255,0]', THEN CHECK FOR LEFT BRACKET
    if ( document.eventsignup.Email.indexOf ( '[', 0 ) == -1 && document.eventsignup.Email.charAt (document.eventsignup.Email.length - 1) == ']') {
        return ( true );
    } else {
        return ( false );
    }
}

function noRightBracket (document.eventsignup.Email) {
    // IF EMAIL ADDRESS IN FORM 'user@[255,255,255,0]', THEN CHECK FOR RIGHT BRACKET
    if (document.eventsignup.Email.indexOf ( '[', 0 ) > -1 && document.eventsignup.Email.charAt (document.eventsignup.Email.length - 1) != ']') {
        return ( true );
    } else {
        return ( false );
    }
}

function noValidPeriod (document.eventsignup.Email) {
    // IF EMAIL ADDRESS IN FORM 'user@[255,255,255,0]', THEN WE ARE NOT INTERESTED
    if (document.eventsignup.Email.indexOf ( '@', 0 ) > 1 && document.eventsignup.Email.charAt (document.eventsignup.Email.length - 1 ) == ']')
    {
    	return ( false );
    }

    // CHECK THAT THERE IS AT LEAST ONE PERIOD IN THE STRING
    if (document.eventsignup.Email.indexOf ( '.', 0 ) == -1)
    {
        return ( true );
    } else {
    
    return ( false );
   }
}

function noValidSuffix(document.eventsignup.Email) {
    // IF EMAIL ADDRESS IN FORM 'user@[255,255,255,0]', THEN WE ARE NOT INTERESTED
    if (document.eventsignup.Email.indexOf('@', 0) > 1 && document.eventsignup.Email.charAt(document.eventsignup.Email.length - 1) == ']') {
        return ( false );
    }

    // CHECK THAT THERE IS A TWO OR THREE CHARACTER SUFFIX AFTER THE LAST PERIOD
    var len = document.eventsignup.Email.length;
    var pos = document.eventsignup.Email.lastIndexOf ( '.', len - 1 ) + 1;
    if ( ( len - pos ) < 2 || ( len - pos ) > 4 ) {
        return ( true );
    } else {
        return ( false );
    }
}