now = new Date

if (now.getHours() < 12) {
    document.write("Good morning and welcome to Webbers: <span class=\"highlight_red\">Somerset, Devon & Cornwall Estate Agents since 1924</span>")
}
else if (now.getHours() < 18) {
    document.write("Good afternoon and welcome to Webbers: <span class=\"highlight_red\">Somerset, Devon & Cornwall Estate Agents since 1924</span>")
}
else if (now.getHours() < 24) {
    document.write("Good evening and welcome to Webbers: <span class=\"highlight_red\">Somerset, Devon & Cornwall Estate Agents since 1924</span>")
}