Edit in JSFiddle

<body>
<div id="i">
</div>
<input type="button" id="b1" value="Press" onclick="i()"/>
</body>
function i()
{
var e=document.createElement("i");
var text=document.createTextNode("Welcome to 20Fingers2Brains.");
e.appendChild(text);
document.getElementById("i").appendChild(e);
}
i
{
color:green;
font-size:30px;
font-weight:bold
}