not able to set ID's to dynamically created labels in JQUERY

not able to set ID's to dynamically created labels in JQUERY

i created a label dynamically in jquery. I need to assign certain styles
to that label. Here i tried to assign a unique ID to that label and apply
styles. But it's not working.
my code is;
Javascript
var lbl = $("<label>").text('Welcome');
lbl.id = "test";
$("#sec").append(lbl);
CSS
#test
{
color:red;
font-size:20px;
}
how to assign ID's to dynamic labels?