<script language="ecmascript" type="text/ecmascript">
var clientContext = null;
var web = null;
function updateWebProperties() {
clientContext = new SP.ClientContext.get_current();
web = clientContext.get_web();
web.set_title('Updated title');
web.update();
clientContext.executeQueryAsync(Function.createDelegate(this, this.onQuerySucceeded), Function.createDelegate(this, this.onQueryFailed));
}
function onQuerySucceeded() {
alert('Web title updated successfully')
}
function onQueryFailed(sender, args) {
alert('Request failed. ' + args.get_message() + '\n' + args.get_stackTrace());
}
</script>
<input id="btnupdateWebProperties" onclick="updateWebProperties()" type="button" value="Updatethe web properties"/>