根据所选值更改文本

我为每个 JavaScript 添加了一个带有文本的元素。有了这个代码：

$(document).ready(function () {
   if ($('welcome_page').length) {
   $('#my_element').after('<tr><td><td><td id="welcome_message">Welcome to my page</td></td></td</tr>');
   }
});

我需要能够根据页面中设置的语言更改文本>欢迎来到我的页面

<select id="languages" onchange="submit();">
<option value="1" selected="">English</option>
<option value="2">Spanish</option>
<option value="3">French</option>
</select>

我已经尝试过这个，但它没有解决问题：

function langChoice(sel){
    var langChange = document.getElementById('languages');
    var langOption = document.getElementById('welcome_message');
        if ( sel.options[sel.selectedIndex].value == "1" ) {
        langOption.innerHTML = "Enter price per month";
        }
        else if ( sel.options[sel.selectedIndex].value == "2" ) {
        langOption.innerHTML = "Enter price per week";
        }
        else if ( sel.options[sel.selectedIndex].value == "3" ) {
        langOption.innerHTML = "Enter price per day";
        }
        else if ( sel.options[sel.selectedIndex].value == "4" ) {
        langOption.innerHTML = "Enter for sale hour";
        }

}

我猜...

访问这个JsFiddle http://jsfiddle.net/L93qwey4/

HTML:

<div id="greet"></div>
<select id="languages">
    <option value="en" >English</option>
    <option value="es" selected>Spanish</option>
    <option value="fr">French</option>
</select>

JS:

var welcome = {
    en:"English",
    es:"Espanol",
    fr:"Francais"
}
$(document).ready(function () {
    $('#greet').html(welcome[$('#languages').val()]);
});

$('#languages').change(function () {
    $('#greet').html(welcome[$('#languages').val()]);
});