// You need this one.

function text2html(str) {
    return str
        .replace(/\</g, '<')
        .replace(/\>/g, '>')
        .replace(/\&/g, '&')
        .replace(/\&apos;/g, '\'')
        .replace(/\"/g, '"');
}

// And the opposite, useful for santizing inputs...

function html2text(str) {
    return str
        .replace(/</g, '<')
        .replace(/>/g, '>')
        .replace(/&/g, '&')
        .replace(/'/g, '&apos;')
        .replace(/"/g, '"');
}