function checkEmail(form)
{
        if (isBlank(form.email.value) || !isEmailValid(form.email.value) ) {
                alert("Please enter a valid Email Address.\nThe email you have typed in does not appear to be valid.");
                form.email.focus();
                return false;
        }
        form.fields_email.value = form.email.value;
        return true;
}

function isBlank(fieldValue)
{
        var blankSpaces = / /g;
        fieldValue = fieldValue.replace(blankSpaces, "");
        return (fieldValue == "") ? true : false;
}

function isEmailValid(fieldValue)
{
        var emailFilter = /^.+@.+\..{2,4}$/;
        var atSignFound = 0;
        for (var i = 0; i <= fieldValue.length; i++)
                if ( fieldValue.charAt(i) == "@" )
                        atSignFound++;
        if ( atSignFound > 1 )
                return false;
        else
                return ( emailFilter.test(fieldValue) && !doesEmailHaveInvalidChar(fieldValue) ) ? true : false;
}

function doesEmailHaveInvalidChar(fieldValue)
{
        var illegalChars = /[\(\)\<\>\,\;\:\\\/\"\[\] ]/;
        return ( illegalChars.test(fieldValue) ) ? true : false;
}