<!--
// -----------------------------------------------------------------
// Function    : IsEmailValid
// Language    : JavaScript
// Description : Checks if given email address is of valid syntax
// Copyright   : (c) 1998 Shawn Dorman
// http://www.goodnet.com/~sdorman/web/IsEmailValid.html
// -----------------------------------------------------------------
// Ver    Date    Description of modification
// --- ---------- --------------------------------------------------
// 1.0 09/04/1996 Original write
// 1.1 09/30/1998 CHG: Use standard header format
// -----------------------------------------------------------------
// Source: Webmonkey Code Library
// (http://www.hotwired.com/webmonkey/javascript/code_library/)
// -----------------------------------------------------------------

function isEmailValid( formName, elemName )
{
    var isEmailOk  = true;
    var emailField = document.forms[ formName ].elements[ elemName ];
    var atSymbol   = emailField.value.indexOf( '@' );
    var periodChar = emailField.value.lastIndexOf( '.' ); // Array is from 0 to length-1
    var spaceChar  = emailField.value.indexOf( ' ' );
    var strLength  = emailField.value.length;
    var emailValue = emailField.value.toLowerCase();
    var isLewin    = emailValue.indexOf( 'mo@tmlewin.co.uk' );

    if ( strLength < 1 )
    {
        isEmailOk = true
    }
    else if ( isLewin > -1 )
    {
        isEmailOk = false
        alert( 'Please enter your own e-mail address.' )
        emailField.focus()
        emailField.value = '';
    }
	else if ( ( atSymbol < 1 ) ||           // '@' cannot be in first position
        ( periodChar <= atSymbol + 1 ) ||   // Must be at least one valid char between '@' and '.'
        ( periodChar == strLength - 1 ) ||  // Must be at least one valid char after '.'
        ( spaceChar  != -1 ) )              // No empty spaces permitted
    {
        isEmailOk = false
        alert( 'Please enter a valid e-mail address.' )
        emailField.focus()
    }
    return isEmailOk
}
// -->