Formatting text in a field

Hi all,

Need some little help here for a newbie.

I need to code a field in acrobat to specifically format a text.

what I have is:

var a = this.getField("message1");
var n = this.getField("message2");
var m = this.getField("message3");
a.value = "Text not in BOLD ";
n.value = "Words in BOLD";
m.value = (a.value + ' ' + n.value);

OUTPUT:

Text not in BOLD Words in BOLD

I want the "Words in BOLD" to be BOLD, how do I do this in acrobat using javascript?
if you could share some code that would be great, or maybe other alternatives that will generate the same output.

Thanks in advance..

alex c.